webadmin: cluster sorting

- Implemented sorting in cluster main tab
- Implemented sorting in cluster sub tabs.
- Fixed bug that would cause invalid SQL to be generated
  when sorting.
- Fixed bug that caused sorting to be ignored when
  updating hosts and VMs for clusters.

Change-Id: Ib7b2d9938a7e9b7e32238a284c0ddca6568b3bdc
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1119873
Signed-off-by: Alexander Wels <awels@redhat.com>