Tablature: proper support for tie/slur- and tie/glissando-constellations (issue2191042)

[Carl . D . Sorensen]

Looks good to me.   Just a comment on the name of the new property to be
added to details.

Thanks,

Carl



http://codereview.appspot.com/2191042/diff/1/scm/define-grobs.scm
File scm/define-grobs.scm (right):

http://codereview.appspot.com/2191042/diff/1/scm/define-grobs.scm#newcode1979
scm/define-grobs.scm:1979: (tied-to . #f)))
tied-from might be a better name than tied-to, since it's the property
of the left-hand note that we're adjusting, rather than the property of
the right hand note.

And maybe something like span-start or spanner-start would be even
better, since I'd guess we want the same behavior to apply for slurs,
glissandos, and bends, all of which are spanners.  And starting the
spanner at the note-head means we want to display the number.

http://codereview.appspot.com/2191042/