fix in harmony.  Improvements in Humdrum documentation

git-svn-id: http://music21.googlecode.com/svn/trunk@3366 5c16147e-a200-11de-b0cc-ab0ad15e60d0
fixed harmony bugs


git-svn-id: http://music21.googlecode.com/svn/trunk@3367 5c16147e-a200-11de-b0cc-ab0ad15e60d0