fix repeat-sign problems introduced with issue 2533

fix repeat-sign problems introduced with issue 2533

This reverts commit d05afb4c0bf29cbd6a98691c9c62afa1604fa4b2,
i.e. applies (a modified version of) 2a872121379fffe7b1cd5d23048b7ea04b4d1f68.
modifications relative to the latter are
- dot size is queried (not hardcoded) when printing a repeat sign
- bar line extent is shrunk not by scaling but cutting
- new regtests for repeat sign in exotic staves
  (non-default staff size, line count, line positions)

[benko.pal, 2012-07-18 20:56:50]

patch enhanced to fix
http://code.google.com/p/lilypond/issues/detail?id=2648

if anyone wants to run regtests, please run both versions on the new regtests.

I'd be happy to split the patch into several commits.

[Keith, 2012-07-19 17:22:21]

LGTM.

I uploaded the two versions of the line-count fixes at
http://codereview.appspot.com/6351107/diff2/1:2001/lily/bar-line.cc
so we can see the difference between sets.

[benko.pal, 2012-07-21 14:34:53]

sorry, after juggling with git branches the new version is at
http://codereview.appspot.com/6419064