rework tom's welcome page to fit in slightly better with riot's UI/UX

* moves login button to top-left
* switches from iframe to a request() to load the welcome page to inherit CSS (probably breaks RTS :/)
* namespace CSS
* change the layout a bit.

src/components/structures/RightPanel.js

@@ -101,10 +101,6 @@ module.exports = React.createClass({
         });
     },
 
-    onLoginClick: function() {
-        dis.dispatch({ action: 'start_login' });
-    },
-
     onRoomStateMember: function(ev, state, member) {
         // redraw the badge on the membership list
         if (this.state.phase == this.Phase.MemberList && member.roomId === this.props.roomId) {
@@ -222,10 +218,6 @@ module.exports = React.createClass({
                             <TintableSvg src="img/minimise.svg" width="10" height="16"/>
                         </div>
                     </div>;
-        } else if (MatrixClientPeg.get().isGuest()) {
-            buttonGroup = <AccessibleButton className="mx_RightPanel_loginButton" element="button" onClick={this.onLoginClick}>
-                Login
-            </AccessibleButton>;
         }
 
         if (!this.props.collapsed) {