_imagingcms.c and display.c didn't compile for me under Python 3.3

These changes at least got compilation working. I'm unsure if Unicode versus Byte functions were used in the right spot, but I think they're correct. Running these through the test suite I'm seeing 20 failures. Uncertain what's happening there as of now.

Also, these changes also rely on the Sane module modifications done by manisandro that are pending in a pull request.