Tremolo cleanup. (issue 44890043)

[dak]

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#newcode33
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#newcode380
scm/music-functions.scm:380: flattened)))))
The body of the let* can be replaced with
  (set! music (make-music 'UnfoldedRepeatedMusic music))

https://codereview.appspot.com/44890043/