Begin making the code portable between Python 2 and Python 3.
Define an explicit sort order for CSS styles, toyplot:axes, and toyplot:data-table, so we can do portable testing.
Checkpoint work on Python 3 compatibility.
More work on Python 3 compatibility.
Another round of Python 3 fixes.
Fix a problem running tests/compare.py in Python 3.
Use repr() to convert floats to strings.  Closes #3.