Fixed some typos
Use version ranges rather than exact versions in setup.py

Libraries should never specify exact requirements because other versions might be needed by the project or its dependencies.
Merge pull request #201 from spookylukey/patch-1

Use version ranges rather than exact versions in setup.py - thanks Luke!
Merge branch 'master' into dev
Upgraded django-mptt to 0.6.1
Added support for django 1.7