* fix(monitoring): enable monitoring only if accessible

Checks first if access to port 19999 is ok, then reloads
and enables monitoring

issue #756

* feat(monitoring): deal better with cached content

Angular was caching port 19999 so it wasn't picking
right monitoring access.
It is still required that the user logs out and in to
refresh monitoring port.

issue #756

* fix(monitoring): check VM status

If the VM is not running, the monitoring settings tab will not be displayed
https://<hostname>/machine/settings/<id_vm>.html#monitoring

Issue #756

* fix(monitoring): check VM status

Issue #756