FIX #731 - Workaround for disconnection

The master issue remains in StropheJS, the disconnecting event seems to
be fired twice (and after disconnect event) and the connexion status
get's wrong.
FIX #732 - vCard management in Hypervisor list view

Agent side :
- don't strip the JID for vm not in roster (will show the hypervisor as
ressource)
- added a query payload (JID) to reply when updating vCard (fix the
null name in notification)

Client Side :
- Change the label in popover to Virtual Machine informations (instead
of Create a virtual machine)
- Update comments / log info
- Redirect a non rostered vm to addSelectedVMToRoster function instead
of editing his vCard.