Refactor keystone_user_role to be lazier

Currently, the entire list of user roles are
cached ASAP. Trying to pre-determine these
is very slow b/c there is no user role list
command in keystone, so you must iterate through
all tenant/user combinations to retrieve the list.

This patch makes the retrieval of all state info
lazy.

Partial-Bug: 1224179
Change-Id: I80a85f3ddf2c41fe447df5682ad31ac4df8f8b59
(cherry picked from commit a0a359801e7248b24d15b3acef3b398d5a2fb65f)
Updated endpoints to support paths and ssl

- Add {public,admin,internal}_url parameters to override other
  {public,admin,internal}_ parameters.
- Also change some 'real_' prefix into '_real' suffix to respect the
coding guide.
- Fixed parsing the ssl/enable value in the provider.
- Update examples

Change-Id: I78d2695eb5cb1287538afe154668da9fe23e62a3
(cherry picked from commit 9cc9e347d5c65a387393995420c7a17a83fbda5a)
Merge "Updated endpoints to support paths and ssl" into stable/havana
Merge "Refactor keystone_user_role to be lazier" into stable/havana