Allow full v3 authentication

Allow authenticating with ids and fetching domain scoped tokens. Changes the
acceptable parameters to more specific parameter names so that _id and _name
parameters can no longer be confused.

This tries to not change the config file and existing credential loading paths.

Closes-Bug: #1420605
Change-Id: If5a889be5826d60bf61dbb84661a5896cb094875
7 files changed