Remove `m.login.token` and `m.login.oauth2` UIA types

AFAIK these have never been implemented. oauth2 lacks enough info to be
sensibly implemented, and `m.login.token` just doesn't make sense.

specification/client_server_api.rst

@@ -431,13 +431,12 @@ User-Interactive Authentication API
 Overview
 <<<<<<<<
 
-Some API endpoints require authentication that
+Some API endpoints require authentication that interacts with the user. The
-interacts with the user. The homeserver may provide many different ways of
+homeserver may provide many different ways of authenticating, such as
-authenticating, such as user/password auth, login via a social network (OAuth2),
+user/password auth, login via a single-sign-on server (SSO), etc. This
-login by confirming a token sent to their email address, etc. This specification
+specification does not define how homeservers should authorise their users but
-does not define how homeservers should authorise their users but instead
+instead defines the standard interface which implementations should follow so
-defines the standard interface which implementations should follow so that ANY
+that ANY client can login to ANY homeserver.
-client can login to ANY homeserver.
 
 The process takes the form of one or more 'stages'. At each stage the client
 submits a set of data for a given authentication type and awaits a response
@@ -663,11 +662,9 @@ Authentication types
 This specification defines the following auth types:
  - ``m.login.password``
  - ``m.login.recaptcha``
- - ``m.login.oauth2``
  - ``m.login.sso``
  - ``m.login.email.identity``
  - ``m.login.msisdn``
- - ``m.login.token``
  - ``m.login.dummy``
 
 Password-based
@@ -744,66 +741,6 @@ To use this authentication type, clients should submit an auth dict as follows:
     "session": "<session ID>"
   }
 
-Token-based
-<<<<<<<<<<<
-:Type:
-  ``m.login.token``
-:Description:
-  The client submits a login token.
-
-To use this authentication type, clients should submit an auth dict as follows:
-
-.. code:: json
-
-  {
-    "type": "m.login.token",
-    "token": "<token>",
-    "txn_id": "<client generated nonce>",
-    "session": "<session ID>"
-  }
-
-
-A client may receive a login ``token`` via some external service, such as email
-or SMS. Note that a login token is separate from an access token, the latter
-providing general authentication to various API endpoints.
-
-Additionally, the server must encode the user ID in the ``token``; there is
-therefore no need for the client to submit a separate username.
-
-The ``txn_id`` should be a random string generated by the client for the
-request. The same ``txn_id`` should be used if retrying the request. The
-``txn_id`` may be used by the server to disallow other devices from using the
-token, thus providing "single use" tokens while still allowing the device to
-retry the request. This would be done by tying the token to the ``txn_id``
-server side, as well as potentially invalidating the token completely once the
-device has successfully logged in (e.g. when we receive a request from the
-newly provisioned access_token).
-
-
-OAuth2-based
-<<<<<<<<<<<<
-:Type:
-  ``m.login.oauth2``
-:Description:
-  Authentication is supported via OAuth2 URLs. This login consists of multiple
-  requests.
-:Parameters:
-  ``uri``: Authorization Request URI OR service selection URI. Both contain an
-  encoded ``redirect URI``.
-
-The homeserver acts as a 'confidential' client for the purposes of OAuth2.  If
-the uri is a ``service selection URI``, it MUST point to a webpage which prompts
-the user to choose which service to authorize with. On selection of a service,
-this MUST link through to an ``Authorization Request URI``. If there is only one
-service which the homeserver accepts when logging in, this indirection can be
-skipped and the "uri" key can be the ``Authorization Request URI``.
-
-The client then visits the ``Authorization Request URI``, which then shows the
-OAuth2 Allow/Deny prompt. Hitting 'Allow' redirects to the ``redirect URI`` with
-the auth code. Homeservers can choose any path for the ``redirect URI``. Once
-the OAuth flow has completed, the client retries the request with the session
-only, as above.
-
 Single Sign-On
 <<<<<<<<<<<<<<
 :Type: