keep decoded images?

[RussellSenior]

It appears that jpeg_stream_rx_stdin_write_to_file.py writes images to /tmp/latest.jpg, with each new image overwriting the last. Seems like with µSD cards being what they are today, there is plenty of room to keep everything that is successfully decoded. Even on a 2GB card, there should be ~300MB of storage space available, and it's hard to find anything less than 8GB these days. People are likely to want to review images after the fact.