Support for m.login.sso

Adds support for the m.login.sso login type, which is handled the same way as
CAS, and also makes it look a bit nicer.

src/components/views/login/CasLogin.js

@@ -1,38 +0,0 @@
-/*
-Copyright 2015, 2016 OpenMarket Ltd
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-'use strict';
-
-import React from 'react';
-import PropTypes from 'prop-types';
-import { _t } from '../../../languageHandler';
-
-module.exports = React.createClass({
-    displayName: 'CasLogin',
-
-    propTypes: {
-      onSubmit: PropTypes.func, // fn()
-    },
-
-    render: function() {
-        return (
-            <div>
-                <button onClick={this.props.onSubmit}>{ _t("Sign in with CAS") }</button>
-            </div>
-        );
-    },
-
-});