Fixes NoteColumn vs SpanBar collisions. (issue 5323062)

[mtsolo]

Reviewers: ,

Message:
Hey all,

This fixes the SpanBar regression ID'd by Phil.  It also fixes a few
other things:

1)      The research I sent out about accidentals not hanging over barlines
(check my e-mails to the list from Oct. 6, Subject: First stab at
getting bar extents right) is actualized here.
2)      The elimination of skyline-vertical-padding corrects a horizontal
spacing issue where the cue-clef takes up too much space in
cue-clef-after-barline.ly and beam-collision-feasible-region.ly
3)      A new regtest, lyrics-pass-under-bar.ly, shows a bug fix for lyrics.

The patch passes regtests (I have yet to do a full doc build).  The only
concern I have is that a lot of regtests that combine tablature and
normal notation are effected but I cannot see how (lots of green, but
nothing looks like it moved).  I don't know why my code is doing this,
and I'm always hesitant to push code that has an effect that I could
neither predict nor explain.  I'll have time to look into it on
Wednesday-ish.  Meanwhile, if anyone has any ideas about what this could
come from, they're welcome!

Cheers,
MS

Description:
Fixes NoteColumn vs SpanBar collisions.

Please review this at http://codereview.appspot.com/5323062/

Affected files:
  input/regression/lyrics-pass-under-bar.ly
  M lily/include/pure-from-neighbor-interface.hh
  M lily/pure-from-neighbor-engraver.cc
  M lily/pure-from-neighbor-interface.cc
  ly/engraver-init.ly
  scm/define-grobs.scm
  M scm/output-lib.scm