Backend Improvements for views & JSON serializing

A hefty bunch of improvements for RTF:

- Model cleanup, improvement, and addition of get_absolute_url & to_json methods
- Added views to get protests by /state/ and /state/city/ URLs
- Added redirect from /id/ > /state/city/ (without making another db lookup)
- Modified protests.html to show both state listings and city detail
- Modified home.html to use new JSON data 

map.html may still have to be updated. Ran out of time to figure out how that was working.