Login templates

Basic blocks, specifically fully working login, registration, image, and content blocks. Specified blocks are working except for:
- I think the CSS needs moved. 
- Default fixtures.
- Tests.
- Easy to use admin.

Please review.

**Important Note**: All html is assume safe. This is probably not non-very-very-trusted user friendly.
Is this a django thing? What benefit is there to having this as a staticmethod instead of a class attribute? Same amount of memory allocation, but I suspect that typing 'ContentBlock.template` will be more convenient that `ContentBlock.template()` if done often enough.