Added Python 3.3 and Django 1.5 support.
Removed print (formerly known as statement) and debugging check.
Another python 3.3 fix.
Added py2/3 trove classifiers to setup.
Added Tox file to verify tests.

Tox file added to verify that tests pass on Python 2.6, 2.7, and 3.3 and on Django 1.4 / 1.5. Copied verbatim from @jacobian https://github.com/jacobian/django-markupfield/blob/1c9b3fd7665417f977e41063666ff21a5dda8596/tox.ini
Removed unneeded dependencies from Tox and updated Django 1.5 to latest.
Merge pull request #93 from jefftriplett/master

Added Python 3 support. Dropped Django 1.3 support.