Re: Optimizes note-heads.cc and introduces robust_symbol2string. (issue 5233042)

[k-ohara5a5a]

http://codereview.appspot.com/5233042/diff/1/lily/note-head.cc
File lily/note-head.cc (right):

http://codereview.appspot.com/5233042/diff/1/lily/note-head.cc#newcode79
lily/note-head.cc:79: out = fm->find_by_name (idx_either);
This performs a second lookup for every note-head.
Move this call to line 61, so you only perform the second lookup if
there is a possibility that it will give a new result.

http://codereview.appspot.com/5233042/