Rename method get_hosts in admin/info/tables.py

There are 2 identical methods defined in admin/info/tables.py,
Rename get_hosts to get_zone_hosts and get_aggregate_hosts.

Change-Id: Ib3d115737400515c4b31178721609055a9658085
Closes-bug: #1262944
Cannot view detailed image with empty name.

After creating an image with empty name (only space characters in the name),
and attempting to view it, the view crashes.
Glance is not returning the name X-Meta-Header on the response if the
name is not set or empty.

Change-Id: I0c55e302d22552e932bdd32e10d00a103d252429
Closes-Bug: 1261367
Modified images list to be sorted alphabetically.

Modified the images drop-down list on the Create Instance modal
dialog to be sorted alphabetically so the user can more easily find
their images.

Closes-Bug: #1262376
Change-Id: I9b1757b5bcebec73159bc643f10767537a3f71bd
Set "remove rule" field to be required in dialog

The dialog can be open from: the "Firewalls"->"Firewall Policies"
->"More" button of a policy->"Remove Rule"

The "remove rule" field should be required, otherwise, user will
hit error when no rule is select. Removed "required=False",
because it is default to True.

Added 'btn-danger' to the button style

Change-Id: Ifa21419bc93818335057bb16ed2683994c6efee7
Closes-Bug: #1252996
Attach volume eventhough the instance is shutoff

It should be possible to attach a volume to a shutoff instance.
Nova CLI (nova volume-attach) allows this and Horizon should be
on par.

Change-Id: Ie7c351e5b23f218d6d10c80b9aebbf233c62b7be
Closes-Bug: 1251255
Merge "Set "remove rule" field to be required in dialog"
Merge "Cannot view detailed image with empty name."
Merge "Rename method get_hosts in admin/info/tables.py"
Merge "Attach volume eventhough the instance is shutoff"
Merge "Modified images list to be sorted alphabetically."