Tremolo cleanup.

Tremolo cleanup.

Scale durations when iterating, not in make-repeat. This means the original
repeat body is intact, so unfold-repeats and display methods no longer need
to undo the scaling.

Build tremolo spanners in Scheme, not C++.

shift-duration-log now clears the cached length, since it changes the length.

\shiftDurations no longer duplicates shift-duration-log.

Open question: can we get rid of the tremolo-type property and just calculate
it when making the spanner?

[dak, 2013-12-26 12:29:43]

Yes, I know, I need to get into the habit of reviewing earlier.  I was looking
at this with the perspective "what if you had to push this yourself", quite
hypothetically.  Mostly cosmetic change suggestions that should not require an
extended review.

Feel free to send me a formatted patch.

https://codereview.appspot.com/44890043/diff/1/lily/chord-tremolo-iterator.cc
File lily/chord-tremolo-iterator.cc (right):

https://codereview.appspot.com/44890043/diff/1/lily/chord-tremolo-iterator.cc...
lily/chord-tremolo-iterator.cc:33: SCM proc = ly_lily_module_constant
("get-tremolo-music-list");
I'd rather use tremolo::get-music-list here.

https://codereview.appspot.com/44890043/diff/1/scm/music-functions.scm
File scm/music-functions.scm (right):

https://codereview.appspot.com/44890043/diff/1/scm/music-functions.scm#newcod...
scm/music-functions.scm:380: flattened)))))
The body of the let* can be replaced with
  (set! music (make-music 'UnfoldedRepeatedMusic music))

[Devon Schudy, 2013-12-27 03:21:53]

Calculate tremolo-type in tremolo::get-music-list rather than storing it as a
property. Simplify make-repeat and remove make-repeated-music.