Most of the differences are in tobytes/tostring naming and expected
behavior of the bytes() constructor. The latter was usually easy to fix
with the right bytes literal.
This is a good preview of what will have to happen in the Python 3 code.
This is Christoph Gohlke's test suite from his personal PIL package found
at http://www.lfd.uci.edu/~gohlke/pythonlibs/.
This is just to bring it in as a separate commit. Future commits will align
it with Pillow.