Rewrite of Midi.c in Python

Rewrite of Midi.c in Python

I rewrote midi.c in Python and tested it on the largest midi file in
IMSLP [1]. On my laptop it takes about 200 ms instead of 50 ms to load
the file, but that's a small fraction of midi2ly's four-second
runtime, and there are a lot of optimizations that can be done in
midi2ly itself. (For example, memoizing the creation of Duration
objects saves about 500 ms.) I think getting rid of the sole occupant
of usr/lib/lilypond/current/python is worth it.

[pkx166h, 2012-12-26 21:08:29]

Actually, I didn't rewrite it - as the comment above suggests - this was from
Ben Rudiak-Gould.

I am helping him at least get some discussion review of his code submission.

This patch has not been patchy-tested and I have just included everything (i.e.
also the .mid files) that were provided by Ben. I have put them in the place
that I thought might be appropriate but I don't really know if this is right or
not.

[benko.pal, 2012-12-27 10:11:52]

SGTM

python/midi.c should be removed (this may involve some make changes)
midi files are seen neither in the web interface, nor in the downloaded patch.

[pkx166h, 2013-01-03 23:34:24]

Ben,

Do you have any newer update to the patch based on the comments? I am a mere
vessel here.

[stefaan.himpe, 2013-01-04 19:28:35]

Issue with the python midi implementation.

https://codereview.appspot.com/7016046/diff/1/scripts/midi.py
File scripts/midi.py (right):

https://codereview.appspot.com/7016046/diff/1/scripts/midi.py#newcode69
scripts/midi.py:69: (0x07, "CUE_POINT"),
Missing support for meta event 0x08? ("PROGRAM CHANGE") 
This meta event e.g. appears inside musescore generated midi files.