Add list method to Bucket
Renamed Bucket.list to get_remote_keys to avoid ambiguity
Make Connection.make_request ignore params set to None
Add prefix parameter to Bucket.get_remote_keys
Major rewrite of rsync

Parameters for rsync have been greatly simplified. No more object
instantiation, all DI baby. Now supports 'dest' parameter
which alows you to rsync to a specific folder on your bucket. Buckets
now take a list of rsync configs instead of just one.