glusterd/cli changes for distributed geo-rep

Commands:
gluster system:: execute gsec_create
gluster volume geo-rep <master> <slave-url> create [push-pem] [force]
gluster volume geo-rep <master> <slave-url> start [force]
gluster volume geo-rep <master> <slave-url> stop [force]
gluster volume geo-rep <master> <slave-url> delete
gluster volume geo-rep <master> <slave-url> config
gluster volume geo-rep <master> <slave-url> status

The geo-replication is distributed. The session will be created, and
gsyncd will be spawned on all relevant nodes, instead of only one
node.

geo-rep: Collecting status detail related data

Added persistent store for saving information about
TotalFilesSynced, TotalSyncTime, TotalBytesSynced

Changes in the status information in socket:
Existing(Ex):
FilesSynced=2;BytesSynced=2507;Uptime=00:26:01;

New(Ex):
FilesSynced=2;BytesSynced=2507;Uptime=00:26:01;SyncTime=0.69978;
TotalSyncTime=2.890044;TotalFilesSynced=6;TotalBytesSynced=143640;

Persistent details stored in
/var/lib/glusterd/geo-replication/${mastervol}/${eSlave}-detail.status

Change-Id: I1db7fc13ffca2e415c05200b0109b1254067f111
BUG: 847839
Original Author: Avra Sengupta <asengupt@redhat.com>
Original Author: Venky Shankar <vshankar@redhat.com>
Original Author: Aravinda VK <avishwan@redhat.com>
Original Author: Amar Tumballi <amarts@redhat.com>
Original Author: Csaba Henk <csaba@redhat.com>
Signed-off-by: Avra Sengupta <asengupt@redhat.com>
Reviewed-on: http://review.gluster.org/5132
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Vijay Bellur <vbellur@redhat.com>