Re-introduced old way of finding leaf-objects.
Added ContentType import to core.models.
Added migration to new type of ContentModel.
Added basic categories app.
Made Tag extend SlugModel.
Fixed the BaseModel typo in Content Model.
Made Category extend off SlugModel
Commented out all PolyMorphic stuff.
Merge branch 'master' into feature/pre-1.1.0
Improved the way events get displayed.
Upped the version to 1.1.0