add hideObjectOnPrint support for lilypond

git-svn-id: http://music21.googlecode.com/svn/trunk@3393 5c16147e-a200-11de-b0cc-ab0ad15e60d0
updated docs and added chords to list of supported objects for hideObjectOnPrint

git-svn-id: http://music21.googlecode.com/svn/trunk@3394 5c16147e-a200-11de-b0cc-ab0ad15e60d0
fix for measure suffixes for Finale musicxml import (possibly others): Finale uses measure numbers X1 etc. for unnumbered measures (pickups midstaff, etc.) and they are now translated to things like 22.X1 if it follows m. 22, etc.

git-svn-id: http://music21.googlecode.com/svn/trunk@3395 5c16147e-a200-11de-b0cc-ab0ad15e60d0