Change CSV file date format to Horizon standard

This patch alters the date format to be 'YYYY-mm-dd', in line with the Overview
query directly by the "Download CSV Summary" button, and the rest of
Horizon.

Change-Id: I39b3bd68eed48ee3b4aace6e75d11f56b69decf4
Closes-Bug: 1387744
Remove 'action_*' for tables.LinkAction

'action_past' and 'action_present' is not needed for LinkAction in
openstack_dashboard/dashboards/admin/hypervisors/compute/tables.py
'EvacuateHost'. We can remove the codes safely.

Change-Id: Ib15224003892c0419e6e2aeeb9390bdf8fda6458
Closes-bug: #1394423
Add values for empty sahara dropdown boxes

Currently if no templates or images are available then the drop down
boxes simply appear empty, this patch adds "No Images Available" and
"No Templates Available" as the first item in each list if they are
empty.

Change-Id: I4bfed9b53f5ac9f031c23a15270b996f7d153be5
Closes-Bug: 1391343
Merge "Add values for empty sahara dropdown boxes"
Merge "Remove 'action_*' for tables.LinkAction"
Merge "Change CSV file date format to Horizon standard"