userportal: VM endless loading

- Fixed issue where if there were no VMs available and you went to
  another tab and then back to the VMs the loading would never end.
- Fixed equals to properly take console user into account instead of
  always returning false even if both VMs had null console users.
- Fixed 'old' grid content from flashing when switching between tabs.

Change-Id: Iae7bc8fcf9b4d875e99f7b4a6264a54ceed9fb7e
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1156103
Signed-off-by: Alexander Wels <awels@redhat.com>