bin: support --vm-status option

Implemented --vm-status command: it will print
to the screen the status of the hosted engine VM
and of the hosts where it may run.

Requires: http://gerrit.ovirt.org/18731
Change-Id: If552f8aacba1744608bd9e87f5f3fafffa6e931d
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>