quarterLength is quarterLengthRational
opFrac -- highly optimized Fractional interface.
python3 passes tests...
fix bugs in m21p conversion from fractions
Merge branch 'master' into mei
WIP-MEI: Tests: Fixed Doctest in mei.__main__._sharpsFromAttr()
WIP-MEI: New: Python 3.3 Compatibility!

Had to add some more "six" and remove some MagicMock(spec_set=), which is too
bad, but at least it works.