Beam collision engraver in lilypond

[address@hidden]

Hey all,

I just git pull'd the source and found beam collision engraver in lilypond.

A couple things:

1) I did not have time yet to address the following comments by Neil.

<snip>

As I suggested previously, you don't need the hack to remove automatic
beams: just acknowledge manual beams instead.  Han-Wen gave some
pointers how you'd do this: use Grob_info::event_cause () to check for a
BeamEvent (using the macro in_event_class ())

BTW, currently you're acknowledging chord tremolo beams (though if you
implement the above they would be filtered out).  Though this might be
useful for accidental avoidance, it will break down for tremolos with
more than two notes due to multiple announce_end_grob () calls in
chord-tremolo-engraver.cc.

</snip>

I think it is important to update the engraver immediately to reflect this.  I won't have time until Saturday, so if someone else could do it, that'd be great!

2)  I saw that a bar line acknowledger was added to the engraver.  I feel that this should be removed; in most scores, beams that cross bar lines collide with the bar line.  See http://www.youtube.com/watch?v=7hEifT_Zy7E , mm. 53-57 & mm. 62-64.

Cheers,

MS