Snapshot component for replication

Implements the snapshot capability for replication by
taking a backup of the master site, then using it
to populate the slave, then turning on replication.

Co-Authored-By: Greg Lucas <glucas@tesora.com>
Co-Authored-By: Nikhil Manchanda <SlickNik@gmail.com>

Partially implements: blueprint replication-v1
Change-Id: Ibd3214b2ffafb250f0cc794c6ee0ff6b0d2ed7da
Merge "Snapshot component for replication"