Support tags/sections for maps tree

[gadesx]

Actually making a game with many maps needs organization, the only way to separate maps is using dummy maps.

Create new maps and call them "Towns", "Dungeon", etc
Unused maps...

So for example, a tree map looks like:

001-Towns
----------Town 01
----------Town 02

002-Dungeons
-----------Dungeon 01

003-Sequence maps
-------------Intro

(A big project needs organization more or less)

Supporting sections you don't need empty maps to use many of them as organization.
Tags idea can be used as
"Completed", "Need Revision", "Debug only", etc
Good after check a project if you forget something (without write a lot of documentation on a calc file or something)

Maybe without need to add this to the lmu file, or map tree.

[Ghabry]

Assuming this is in the LMT there could be just a new type. There is already "Area" which does not create a new map file (but does not support childs)