Show how to properly support the Gonville font. (issue246041)

[hanwenn]

Reviewers: ,

Message:
Hi,

I didnt see the mail from the review come through, so: please review.

Description:
Show how to properly support the Gonville font.

Example in input/gonville.ly; it is not part of the regtest, since we
currently do not ship Gonville.  This still does not work for alphabet
glyphs, since those are still hardcoded to feta-alphabet, and are
loaded through Pango.

Rename aybabtu font to emmentaler-brace.


Pass a list of design sizes into add-music-fonts function.

This prepares for music fonts that come in just one design size.

Please review this at http://codereview.appspot.com/246041/show

Affected files:
  M ROADMAP
  A input/gonville.ly
  D input/regression/gonville.ly
  M lily/all-font-metrics-scheme.cc
  M lily/font-metric-scheme.cc
  M mf/GNUmakefile
  A + mf/emmentaler-brace.pe.in
  scm/define-grob-properties.scm
  scm/font.scm
  scm/framework-ps.scm
  scm/lily-library.scm