Fixed some problems with relative paths in the metadata cache.


git-svn-id: http://music21.googlecode.com/svn/trunk@3590 5c16147e-a200-11de-b0cc-ab0ad15e60d0
Reinstituted "stub" metadata entries, representing multi-work opuses in the 
corpus, for metadata caching optimization.

We now cache all time signatures, key signatures and tempi in each analyzed
corpus entry, as well as their ambitus.


git-svn-id: http://music21.googlecode.com/svn/trunk@3591 5c16147e-a200-11de-b0cc-ab0ad15e60d0
Updated freeze/thaw attribute listing for RichMetadata.


git-svn-id: http://music21.googlecode.com/svn/trunk@3592 5c16147e-a200-11de-b0cc-ab0ad15e60d0
Improved metadata caching logic, and fixed various doctests.

Running test/test.py now results in *0* errors on Python 2.7.5 / OSX 10.8!


git-svn-id: http://music21.googlecode.com/svn/trunk@3593 5c16147e-a200-11de-b0cc-ab0ad15e60d0
replaced code for getElementsByOffset to allow zero-length objects to be found in a zero-length search -- see bug https://groups.google.com/forum/#!topic/music21list/RGOupcvz5x8


git-svn-id: http://music21.googlecode.com/svn/trunk@3594 5c16147e-a200-11de-b0cc-ab0ad15e60d0
Some cleanups for the new getElementsByOffset calls.  Many small cleanups to small errors or pydev/pylint perceived errors.

git-svn-id: http://music21.googlecode.com/svn/trunk@3595 5c16147e-a200-11de-b0cc-ab0ad15e60d0