Update receiver side models and create migration.
add better exception handling for 404 and 500 in rest_util.
Implement replica_share API
Receive trail api should accept more status update attributes.
snapshots of type 'receiver' should be created without btrfs snapshot.
Update share API to take replica attribute for replica shares.
update share_regex to accept - and .
Add ReplicaShare and ReceiveTrail views.
Add rshare, snapshot and share utility methods for receiver.
Sender should also tell the receiver if it's sending incremental fsdata.
Make receiver fault tolerant and add trail along the way.