- y-refpoint for rests should be the 4th staffline (gclef: b')
	- more symbols
	  * flags
	  * clefs
	  * some scripts:
	    - {up, down}bow
	    - toe/heel
	    - piano pedals,
	    - braces.
	    - trills
	  * coda signs.
	  * 0 - 9

	- move to OpusTeX fonts ?  (no!)
	- include important spacing dims in TFM? 
	- lilyrules.mf for different rules (lines) ?
	- check out Adobe Sonata/Petrucci font layout.  They are the
standard for Music fonts
	- hack up GS to do round pixels iso. square pixels.