Set percent counter visibility using repeatCountVisibility.

[hanwenn]

Reviewers: Neil Puttock,

Message:
LGTM


http://codereview.appspot.com/8849/diff/1/3
File lily/percent-repeat-engraver.cc (right):

http://codereview.appspot.com/8849/diff/1/3#newcode228
Line 228: return (ly_is_procedure (proc) && to_boolean (scm_call_1
(proc, count)));
add a context argument too, so the function can look around on its own
if it needs to.

Description:
Set percent counter visibility using repeatCountVisibility.

Please review this at http://codereview.appspot.com/8849

Affected files:
  A input/regression/repeat-percent-count-visibility.ly
  M lily/percent-repeat-engraver.cc
  M ly/engraver-init.ly
  M scm/define-context-properties.scm
  M scm/output-lib.scm