Allow form to stay modal after uploading file

Use HTML5 FormData browser API together with FileList API to make
possible AJAX file uploads (see http://tinyurl.com/kmznw2n on FormData
examples). Feature detection is the same as in jQuery Form Plugin (see
http://tinyurl.com/n6v5dsx). Browsers without FormData support (most
importantly, IE<10) do not support setting custom AJAX request
headers, so form with File Upload field will lose modality in them
anyway.

Change-Id: Id3b91a49a71c6de314c6a7cbee5357fe13679490
Closes-Bug: #1158501
Add Volume Snapshots table to Admin Volumes

This is part 2 of the work for the BP. The Volume Snapshots table
resides inside the new "Volume Snapshots" tab which is the second tab
within the Admin Volumes panel. There are two table actions: "Delete
Volume Snapshot" and "Update Volume Snapshot Status". The Update
Volume Snapshot Status action implements a cinder command that was
only available through CLI as per stated in the BP.

Change-Id: Ife2da2c142467e47a7ac5bfcb8a477ff578b4d39
Partial-Implements: blueprint cinder-reset-snapshot-state
Closes-Bug: #1332077
Change value of None in encrypted volume field from "Maybe" to "-"

This makes it clearer to the user that information about whether the volume is
encrypted or not is not known.

Implemented by moving from standard yesno filter to filtering the value of the
encrypted field in the function get_encrypted_value

Change-Id: I14d157752e565fce68248af6c53a586ccf6c39be
Closes-Bug: 1354583
Imported Translations from Transifex

Change-Id: I579ee5040128b45fa10beca4980feb6696095938
Merge "Add Volume Snapshots table to Admin Volumes"
Merge "Allow form to stay modal after uploading file"
Merge "Imported Translations from Transifex"
Add Neutron distributed virtual router

DVR (distributed virtual router) related column and menu
are displayed on when DVR is enabled. To enable DVR support,
you need to set enable_distribute_router in local_settings to True
and run Neutron with DVR support.

neutron_policy.json is updated to allow policy check for DVR attribute.

Implements blueprint enhance-horizon-for-dvr
Change-Id: I422508395d35a6160c671df616aa6a6e90e5de36