DynamicTextSpanners should end like hairpins

[Jon Arnold]

> I'm not top posting.

DynamicTextSpanners in their current state will prevent hairpins from being 
produced properly if the space is small.

The DynamicTextSpanner should have the same right boundary as a hairpin (i.e. a 
\cresc should end at the same place as a \< ). They should also behave the same 
way at barlines.

The following example demonstrates the behavior of a \cresc and a crescendo 
hairpin at the same place. Notice that the following diminuendo hairpin is cut 
off in the first example. The final example shows the proper diminuendo 
hairpin, 
as the \cresc is ended a beat earlier than in the original music.

The second set of examples shows similar behavior but ending at a barline.

http://dl.dropbox.com/u/143104/dynamicSpannerIssue.ly
http://dl.dropbox.com/u/143104/dynamicSpannerIssue.png