feature req: volta bar numbering options

[Mark Polesky]

Developers,

I'd like to be able to set how volta alternative measures
are numbered. Currently (as of 2.11.65), measures are
counted as if there were no repeat signs, but I can't find a
single example of this if the engraved world. Moreover,
every example of numbered-measure scores I found counted the
bars such that each alternative within a group starts with
the same measure number. I don't have Gardner Read with me
at the moment, but I assume this is the common practice.

____________________________________________________________


I propose this syntax:
  \set voltaBarNumbering = #'reset

with the following 3 options:

  'reset (proposed default)
      count bars so that each alternative within 
      a group starts with the same measure number.

  'unfold
      count bars as if "volta" were "unfold"

  'ignore (current behavior)
      count bars as if there were no repeat signs

____________________________________________________________


Any thoughts?

- Mark