The plugin detection at the top of openstackclient.api.auth did not
detect the plugins at the bottom of that file because, surprise,
they had not been declared yet so the entry points were ignored.

Move both plugin subclasses into openstackclient.api.auth_plugin.

Fix a problem with the password callback that was otherwise made
worse with this change.

Closes-Bug: 1428912
Change-Id: Idc3b72534071e0013c8922884a8bc14137509a0f

When we got picky with the auth arguments we broke using help without
any auth config supplied.  This rearranges things a bit to do the argument
checking when the deferred auth request to Identity occurs so commands
that do not need auth have a chance to live short but useful lives.

Closes-Bug: #1399588
Change-Id: I8ceac491cf65e25eddb62ab2713f471fe686756d

Change-Id: Ieff86f841623e1ce34b79c66bc5e8b1b239fa3e9

Setting up auth options can be complicated, and we currently don't
do any checking before we build all our auth parameters to send off
to keystoneclient. We should do some basic checking to guide new
users.

Change-Id: I9c88f1c9637b3870c151952ecc797aaf65be271a
Closes-Bug: #1400531

This subclasses KSC's generic Password plugin to allow version discovery with
default Keystone configurations that leave admin_endpoint and public_endpoint
at the default values (http://localhost:xxxx).  This patch copies the scheme
and netloc from the original auth_url into the URL returned from version
discovery if the returned netloc begins with 'localhost'.

Due to the specific nature of this review, the Keystone team is not
inclned to include it in keystoneclient so it is addressed here.

Closes-bug: #1410364
Change-Id: I877fe74d86aab3a63122a07b77d1302a007f5b30

Help for option --os-auth-type doesn't specify what environment variable
configures it. This patch fixes that.

Change-Id: Id2e29e477d5ca56339bd777fb73b5af13788615b

User's don't know what a plugin is.

* Internally, os_auth_type and/or auth_type represents what the
  user supplied.
* auth_plugin_name is the name of the selected plugin
* auth_plugin is the actual plugin object

Plugin selection process:
* if --os-auth-type is supplied:
  * if it matches against an available plugin, done
  * (if it can map to an availble plugin type, done; TODO in a followup)
* if --os-auth-type is not supplied:
  * if --os-url and --os-token are supplied, select 'token_endpoint'
  * if --os-username supplied, select identity_api_version + 'password'
  * if --os-token supplied, select identity_api_version + 'token'

Change-Id: Ice4535214e311ebf924087cf77f6d84d76f5f3ee

* Remove the auth option checks as the auth plugins will validate
  their own options
* Move the initialization of client_manager to the end of
  initialize_app() so it is always called.  Note that no attempts
  to actually authenticate occur until the first use of one of the
  client attributes in client_manager.  This leaves
  initialize_clientmanager() (formerly uathenticate_user()) empty
  so remove it.
* Remove interact() as the client_manager has already been created
  And there is nothing left.
* prepare_to_run_command() is reduced to trigger an authentication
  attempt for the best_effort auth commands, currently the only
  one is 'complete'.
* Add prompt_for_password() to ask the user to enter a password
  when necessary.  Passed to ClientManager in a new kward pw_func.

Bug: 1355838
Change-Id: I9fdec9144c4c84f65aed1cf91ce41fe1895089b2