message: tell guests they can't use filepanel until they register
diff: @@ -90,7 +90,11 @@ var FilePanel = React.createClass({
  },
  render: function() {
  - if (this.noRoom) {
  + if (MatrixClientPeg.get().isGuest()) {
  + return <div className="mx_FilePanel mx_RoomView_messageListWrapper">
  + <div className="mx_RoomView_empty">You must register to use this functionality</div>
  + </div>;
  + } else if (this.noRoom) {
  return <div className="mx_FilePanel mx_RoomView_messageListWrapper">
  <div className="mx_RoomView_empty">You must join the room to see its files</div>
  </div>;
  