Issue 4039: Improvements to magnifyMusic and magnifyStaff. (issue 115480043 by address@hidden)

[markpolesky]

Reviewers: ,

Message:
Here are some improvements to magnifyMusic and magnifyStaff.  Nothing
major, but please have a look.  Also, I'm still hoping to get a little
more discussion on my earlier -devel thread:
http://lists.gnu.org/archive/html/lilypond-devel/2014-07/msg00260.html

Thanks,
Mark

Description:
Scale tablature half-note double-stems.
Scale baseline-skip and word-space props.*
Add regtests.

*this requires adding text-interface to InstrumentName, which is the
subject of Issue 4038.

Issue 4039 on tracker:
http://code.google.com/p/lilypond/issues/detail?id=4039

Please review this at https://codereview.appspot.com/115480043/

Affected files (+170, -36 lines):
  A input/regression/magnifyMusic-tablature-double-stems.ly
  A input/regression/magnifyMusic-text-interface.ly
  A input/regression/magnifyStaff-tablature-double-stems.ly
  A input/regression/magnifyStaff-text-interface.ly
  M ly/music-functions-init.ly
  M scm/define-grobs.scm
  M scm/music-functions.scm