Fixes to midi2ly.py: better note lengths, now supports meter changes (issue 325800043 by address@hidden)

[pkx166h]

Reviewers: ,

Message:
This fails a basic 'make' when applied to current master.

Also Christopher, if and when you submit a new patch, can you clean up
the whitespace errors that are also reported ('git apply' squelches
some, but I can see that you are using tabs in the diff on Rietveld and
this will cause comments by other devs). Also see:

http://lilypond.org/doc/v2.19/Documentation/contributor-big-page#policy-decisions-_0028finished_0029



regards

Description:
Fixes to midi2ly.py: better note lengths, now supports meter changes

(1) Note lengths currently are fractions like 61/120. If the numerator
can be changed by 1 to get a better fraction, it is done. Quarter
notes are also replaced with eighths/sixteenths if appropriate.
For example: a duration of 4*61/120 is changed to 4*1/2 and then
to 8. (2) Current version of midi2ly does not support meter changes.
Patch does.

Resolves: #5119

Please review this at https://codereview.appspot.com/325800043/

Affected files (+87, -50 lines):
  M scripts/midi2ly.py