deploy: Spit gnt-node add

..into gnt-node add that adds the node if not already added
and gnt-node modify that makes it vm-capable and master-capable.

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
deploy: Reset status and cleanup before vcluster

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>