Enable settings/change password on keystone v3

There is a new API in v3 for users to update their own password.

Change-Id: I30e1f4682dab6e29968f38f04fa71e0e3720d5e1
Closes-Bug: #1239757
Make "Gigabytes" quotas description more meaningful

"Gigabytes" quota entry comes from Cinder, but Horizon displays
quotas from various projects and "Gigabytes" is hard to understand.
This commit changes it to "Total Size of Volumes and Snapshots (GB)".
From the same reason, "Snapshots" is renamed to "Volume Snapshots".

LUKS Volume quotas are also renamed for consistency.

Change-Id: I7289783b75d324980c0ca80b71835ab602efc354
Closes-Bug: #1298934
Merge "Enable settings/change password on keystone v3"
Merge "Make "Gigabytes" quotas description more meaningful"