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.
It's a consistency thing. SearchBoxBlock is already touching on what I'm afraid might be a thing later on, where the templates are based on custom parts of the block. With all of the dependencies on render() and it being such a small, time consuming change I just figured I'd plan for it now rather than refactor later.