Only fall back to localhost if the URI is "redis_cache.cache://"

django-redis-cache for django 1.3 (not compatible with 1.2 : new parameters to methods in BaseCache)

Thanks to Kami for the report and Jezdez for being awesome.

CACHE_BACKEND = 'redis_cache.cache://127.0.0.1:6379?db=2'

- Got rid of _prepare_key and _prepare_value
- Started using the base64 module directly
- Use the highest pickle protocol available
- Added a set_many method
- Added a delete_many method
- Added an expire method
- Made get_many return a dictionary as required

Got rid of the incr and decr implementation since we can't really increment/decrement the base64'd values.