Make Task state translatable.

The Task state None is currently not translated because it is the
literal value None.  Update to make sure it gets displayed as translated.
Also add in other missing task_states: 'reboot_pending', 'reboot_started',
'reboot_pending_hard', 'reboot_started_hard'

Change-Id: I4f9f8d22711896b2e9d39ef1bf5e803ca7bcbc0a
Closes-Bug: #1392848
Ability to change modal form backdrop element behavior

By default modal form is closed after clicking outside of it on a dark
backdrop (data-backdrop="true"). For the forms with a lot of fields
this could lead to a loss of data the user had entered before he has
unintentionally clicked outside of the form. So more preferable option
for such forms (and workflows/client-side modals) would be
data-backdrop="static".

DocImpact
Change-Id: I56fca9131a4e4d3991d53184ee1332e84138cdc2
Partially-Implements: blueprint form-template-to-view
Related-Bug: #1062065
Small performance improvement

We can use search_opts for volume_list and volume_snapshot_list
instead of filtering the results after we get the whole list to
improve the performance.

Change-Id: Ieb7833038228c97f7415bd57ecd353e218f00cdd
Closes-bug: #1401013
Make admin_state translatable

In several panels the network admin state is hardcoded to UP/DOWN,
this patch aims to make the admin_state translatable.

Change-Id: Ia0e5ba02a4980c1db0d914e2689956feee5fb718
Closes-bug: #1390207
Merge "Make Task state translatable."
Merge "Ability to change modal form backdrop element behavior"
Merge "Make admin_state translatable"
Merge "Small performance improvement"