License the repo under the BSD-3-Clause license (#186)

I also took the occasion to change license headers to SPDX-style tags (see https://spdx.github.io/spdx-spec/v2.3/file-tags/), that are more manageable and machine readable. 

As a result of the cleanup I deleted the authors name from the headers as it is more mantainable to just store this information in git, if there is any problem in this we can re-introduce them with a follow-up PR, using the `SPDX-FileContributor:` tag.

LICENSE

@@ -1,165 +1,28 @@
-                   GNU LESSER GENERAL PUBLIC LICENSE
-                       Version 3, 29 June 2007
-
- Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
-
-
-  This version of the GNU Lesser General Public License incorporates
-the terms and conditions of version 3 of the GNU General Public
-License, supplemented by the additional permissions listed below.
-
-  0. Additional Definitions.
-
-  As used herein, "this License" refers to version 3 of the GNU Lesser
-General Public License, and the "GNU GPL" refers to version 3 of the GNU
-General Public License.
-
-  "The Library" refers to a covered work governed by this License,
-other than an Application or a Combined Work as defined below.
-
-  An "Application" is any work that makes use of an interface provided
-by the Library, but which is not otherwise based on the Library.
-Defining a subclass of a class defined by the Library is deemed a mode
-of using an interface provided by the Library.
-
-  A "Combined Work" is a work produced by combining or linking an
-Application with the Library.  The particular version of the Library
-with which the Combined Work was made is also called the "Linked
-Version".
-
-  The "Minimal Corresponding Source" for a Combined Work means the
-Corresponding Source for the Combined Work, excluding any source code
-for portions of the Combined Work that, considered in isolation, are
-based on the Application, and not on the Linked Version.
-
-  The "Corresponding Application Code" for a Combined Work means the
-object code and/or source code for the Application, including any data
-and utility programs needed for reproducing the Combined Work from the
-Application, but excluding the System Libraries of the Combined Work.
-
-  1. Exception to Section 3 of the GNU GPL.
-
-  You may convey a covered work under sections 3 and 4 of this License
-without being bound by section 3 of the GNU GPL.
-
-  2. Conveying Modified Versions.
-
-  If you modify a copy of the Library, and, in your modifications, a
-facility refers to a function or data to be supplied by an Application
-that uses the facility (other than as an argument passed when the
-facility is invoked), then you may convey a copy of the modified
-version:
-
-   a) under this License, provided that you make a good faith effort to
-   ensure that, in the event an Application does not supply the
-   function or data, the facility still operates, and performs
-   whatever part of its purpose remains meaningful, or
-
-   b) under the GNU GPL, with none of the additional permissions of
-   this License applicable to that copy.
-
-  3. Object Code Incorporating Material from Library Header Files.
-
-  The object code form of an Application may incorporate material from
-a header file that is part of the Library.  You may convey such object
-code under terms of your choice, provided that, if the incorporated
-material is not limited to numerical parameters, data structure
-layouts and accessors, or small macros, inline functions and templates
-(ten or fewer lines in length), you do both of the following:
-
-   a) Give prominent notice with each copy of the object code that the
-   Library is used in it and that the Library and its use are
-   covered by this License.
-
-   b) Accompany the object code with a copy of the GNU GPL and this license
-   document.
-
-  4. Combined Works.
-
-  You may convey a Combined Work under terms of your choice that,
-taken together, effectively do not restrict modification of the
-portions of the Library contained in the Combined Work and reverse
-engineering for debugging such modifications, if you also do each of
-the following:
-
-   a) Give prominent notice with each copy of the Combined Work that
-   the Library is used in it and that the Library and its use are
-   covered by this License.
-
-   b) Accompany the Combined Work with a copy of the GNU GPL and this license
-   document.
-
-   c) For a Combined Work that displays copyright notices during
-   execution, include the copyright notice for the Library among
-   these notices, as well as a reference directing the user to the
-   copies of the GNU GPL and this license document.
-
-   d) Do one of the following:
-
-       0) Convey the Minimal Corresponding Source under the terms of this
-       License, and the Corresponding Application Code in a form
-       suitable for, and under terms that permit, the user to
-       recombine or relink the Application with a modified version of
-       the Linked Version to produce a modified Combined Work, in the
-       manner specified by section 6 of the GNU GPL for conveying
-       Corresponding Source.
-
-       1) Use a suitable shared library mechanism for linking with the
-       Library.  A suitable mechanism is one that (a) uses at run time
-       a copy of the Library already present on the user's computer
-       system, and (b) will operate properly with a modified version
-       of the Library that is interface-compatible with the Linked
-       Version.
-
-   e) Provide Installation Information, but only if you would otherwise
-   be required to provide such information under section 6 of the
-   GNU GPL, and only to the extent that such information is
-   necessary to install and execute a modified version of the
-   Combined Work produced by recombining or relinking the
-   Application with a modified version of the Linked Version. (If
-   you use option 4d0, the Installation Information must accompany
-   the Minimal Corresponding Source and Corresponding Application
-   Code. If you use option 4d1, you must provide the Installation
-   Information in the manner specified by section 6 of the GNU GPL
-   for conveying Corresponding Source.)
-
-  5. Combined Libraries.
-
-  You may place library facilities that are a work based on the
-Library side by side in a single library together with other library
-facilities that are not Applications and are not covered by this
-License, and convey such a combined library under terms of your
-choice, if you do both of the following:
-
-   a) Accompany the combined library with a copy of the same work based
-   on the Library, uncombined with any other library facilities,
-   conveyed under the terms of this License.
-
-   b) Give prominent notice with the combined library that part of it
-   is a work based on the Library, and explaining where to find the
-   accompanying uncombined form of the same work.
-
-  6. Revised Versions of the GNU Lesser General Public License.
-
-  The Free Software Foundation may publish revised and/or new versions
-of the GNU Lesser General Public License from time to time. Such new
-versions will be similar in spirit to the present version, but may
-differ in detail to address new problems or concerns.
-
-  Each version is given a distinguishing version number. If the
-Library as you received it specifies that a certain numbered version
-of the GNU Lesser General Public License "or any later version"
-applies to it, you have the option of following the terms and
-conditions either of that published version or of any later version
-published by the Free Software Foundation. If the Library as you
-received it does not specify a version number of the GNU Lesser
-General Public License, you may choose any version of the GNU Lesser
-General Public License ever published by the Free Software Foundation.
-
-  If the Library as you received it specifies that a proxy can decide
-whether future versions of the GNU Lesser General Public License shall
-apply, that proxy's public statement of acceptance of any version is
-permanent authorization for you to choose that version for the
-Library.
+BSD 3-Clause License
+
+Copyright (c) Fondazione Istituto Italiano di Tecnologia (IIT)
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

MATLAB/Logger/initLogger.m

@@ -2,17 +2,8 @@
 % /**
 %  * Copyright (C): copyright 2018 iCub Facility - Istituto Italiano di Tecnologia
 %  * @author: Giulio Romualdi
-%  * Permission is granted to copy, distribute, and/or modify this program
-%  * under the terms of the GNU General Public License, version 2 or any
-%  * later version published by the Free Software Foundation.
-%  *
-%  * A copy of the license can be found at
-%  * http://www.robotcub.org/icub/license/gpl.txt
-%  *
-%  * This program is distributed in the hope that it will be useful, but
-%  * WITHOUT ANY WARRANTY; without even the implied warranty of
-%  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-%  * Public License for more details
+%  * SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+%  * SPDX-License-Identifier: BSD-3-Clause
 %  */
 %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 

src/JoypadModule/include/WalkingControllers/JoypadModule/Module.h

@@ -1,10 +1,5 @@
-/**
- * @file JoypadModule.hpp
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2018 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2018
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 #ifndef WALKING_JOYPAD_MODULE_HPP
 #define WALKING_JOYPAD_MODULE_HPP

src/JoypadModule/src/Module.cpp

@@ -1,10 +1,5 @@
-/**
- * @file JoypadModule.cpp
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2018 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2018
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 // YARP
 #include <yarp/os/LogStream.h>

src/JoypadModule/src/main.cpp

@@ -1,10 +1,5 @@
-/**
- * @file main.cpp
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2018 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2018
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 // YARP
 #include <yarp/os/LogStream.h>

src/KinDynWrapper/include/WalkingControllers/KinDynWrapper/Wrapper.h

@@ -1,10 +1,5 @@
-/**
- * @file Wrapper.h
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2018 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2018
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 #ifndef WALKING_CONTROLLERS_KINDYN_WRAPPER_WRAPPER_H
 #define WALKING_CONTROLLERS_KINDYN_WRAPPER_WRAPPER_H

src/KinDynWrapper/src/Wrapper.cpp

@@ -1,10 +1,5 @@
-/**
- * @file Wrapper.cpp
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2018 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2018
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 // std
 #include <cmath>

src/RetargetingHelper/include/WalkingControllers/RetargetingHelper/Helper.h

@@ -1,10 +1,5 @@
-/**
- * @file Helper.h
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2019 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2019
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 #ifndef WALKING_CONTROLLERS_RETARGETING_HELPER_HELPER_H
 #define WALKING_CONTROLLERS_RETARGETING_HELPER_HELPER_H

src/RetargetingHelper/src/Helper.cpp

@@ -1,10 +1,5 @@
-/**
- * @file Helper.h
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2019 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2019
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 #include <yarp/os/LogStream.h>
 #include <yarp/sig/Vector.h>

src/RobotInterface/include/WalkingControllers/RobotInterface/Helper.h

@@ -1,10 +1,5 @@
-/**
- * @file Helper.h
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2019 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2019
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 #ifndef WALKING_CONTROLLERS_ROBOT_HELPER_HELPER_H
 #define WALKING_CONTROLLERS_ROBOT_HELPER_HELPER_H

src/RobotInterface/src/Helper.cpp

@@ -1,10 +1,5 @@
-/**
- * @file Helper.h
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2024 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2024
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 #include <iDynTree/Utils.h>
 #include <iDynTree/EigenHelpers.h>

src/SimplifiedModelControllers/include/WalkingControllers/SimplifiedModelControllers/DCMModelPredictiveController.h

@@ -1,10 +1,5 @@
-/**
- * @file DCMModelPredictiveController.hpp
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2018 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2018
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 
 #ifndef WALKING_CONTROLLERS_SIMPLIFIED_MODEL_CONTROLLERS_DCM_MPC_H

src/SimplifiedModelControllers/include/WalkingControllers/SimplifiedModelControllers/DCMReactiveController.h

@@ -1,10 +1,5 @@
-/**
- * @file DCMReactiveController.hpp
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2018 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2018
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 #ifndef WALKING_CONTROLLERS_SIMPLIFIED_MODEL_CONTROLLERS_DCM_REACTIVE_CONTROLLER_H
 #define WALKING_CONTROLLERS_SIMPLIFIED_MODEL_CONTROLLERS_DCM_REACTIVE_CONTROLLER_H

src/SimplifiedModelControllers/include/WalkingControllers/SimplifiedModelControllers/MPCSolver.h

@@ -1,10 +1,5 @@
-/**
- * @file MPCSolver.h
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2018 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2018
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 #ifndef WALKING_CONTROLLERS_SIMPLIFIED_MODEL_CONTROLLERS_MPC_SOLVER_H
 #define WALKING_CONTROLLERS_SIMPLIFIED_MODEL_CONTROLLERS_MPC_SOLVER_H

src/SimplifiedModelControllers/include/WalkingControllers/SimplifiedModelControllers/ZMPController.h

@@ -1,10 +1,5 @@
-/**
- * @file ZMPController.h
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2018 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2018
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 #ifndef WALKING_CONTROLLERS_SIMPLIFIED_MODEL_CONTROLLERS_ZMP_CONTROLLER_H
 #define WALKING_CONTROLLERS_SIMPLIFIED_MODEL_CONTROLLERS_ZMP_CONTROLLER_H

src/SimplifiedModelControllers/src/DCMModelPredictiveController.cpp

@@ -1,10 +1,5 @@
-/**
- * @file WalkingDCMModelPredictiveController.cpp
- * @authors Giulio Romualdi <[email protected]>
- * @copyright 2018 iCub Facility - Istituto Italiano di Tecnologia
- *            Released under the terms of the LGPLv2.1 or later, see LGPL.TXT
- * @date 2018
- */
+// SPDX-FileCopyrightText: Fondazione Istituto Italiano di Tecnologia (IIT)
+// SPDX-License-Identifier: BSD-3-Clause
 
 // std
 #ifndef NOMINMAX