Streamlined metadata.py.


git-svn-id: http://music21.googlecode.com/svn/trunk@3557 5c16147e-a200-11de-b0cc-ab0ad15e60d0
Streamlining metadata.py.


git-svn-id: http://music21.googlecode.com/svn/trunk@3558 5c16147e-a200-11de-b0cc-ab0ad15e60d0