Make the Settings form fully translatable

Also switch to using the _() gettext convention for marking
translatable strings.

Fixes bug #1183795

Change-Id: I1450cbd8410108ed95d431243b8a84541bdedbdb
Adding CRUD for roles

This adds basic support for CRUD on roles for admin users.

The CRUD operations in keystone are only exposed without an
extension in V3.  So if the python-keystoneclient does not support
V3, the panel will not be registered.

Support for blocking create, edit and delete in LDAP case added.

Implements: blueprint admin-role-crud

Change-Id: Ibd727df1392ab9a748ab585620c1ff3dc57d3efb
Fixes boot from volume without image

Fixes Bug #1163566

I've also disabled booting from volume with an image specified
although Nova does support this, I've chosen to still disable it in
Horizon because it doesn't make much sense. Tihomir Trifonov also
noted this.

Change-Id: I17f3edbbb0cabe1cf415484f32016aab7a332ed4
Merge "Make the Settings form fully translatable"
Merge "Fixes boot from volume without image"
Merge "Adding CRUD for roles"