simplifications but i'm not sure it works

- change license to mit
- no more .in files, and .py always has __version__
- code is vaguely better, but not by much...
passes basic pep8 analysis now
package and setup.py improvements, and --audio-track and --video-track
simplify things, use pandoc, add codesetup.py
allow choosing path to mp4creator and MP4Box
better help, and forward mkvinfo or something