Added more glyphs to TextNote

Added [Caesura](http://en.wikipedia.org/wiki/Caesura) (straight/curved) marks
Added [breath marks](http://en.wikipedia.org/wiki/Breath_mark) (comma/tick)
Added pedal annotations (open/close) 
Added lower mordent

Expanded `Vex.Flow.Font` to include missing glyphs

![image](https://cloud.githubusercontent.com/assets/1631625/2759443/c74c3dd2-c9a0-11e3-8ae6-daf9ca07ee26.png)