message: Limit the length of topics and names in the RoomDirectory
diff: @@ -34,6 +34,9 @@ import { _t } from '../../languageHandler';
  import {instanceForInstanceId, protocolNameForInstanceId} from '../../utils/DirectoryUtils';
  +const MAX_NAME_LENGTH = 80;
  +const MAX_TOPIC_LENGTH = 160;
  +
  linkifyMatrix(linkify);
  module.exports = React.createClass({
  @@ -390,7 +393,6 @@ module.exports = React.createClass({
  const self = this;
  let guestRead; let guestJoin; let perms;
  for (let i = 0; i < rooms.length; i++) {
  - const name = rooms[i].name || get_display_alias_for_room(rooms[i]) || _t('Unnamed room');
  guestRead = null;
  guestJoin = null;
  @@ -410,7 +412,15 @@ module.exports = React.createClass({
  perms = <div className="mx_RoomDirectory_perms">{guestRead}{guestJoin}</div>;
  }
  + let name = rooms[i].name || get_display_alias_for_room(rooms[i]) || _t('Unnamed room');
  + if (name.length > MAX_NAME_LENGTH) {
  + name = `${name.substring(0, MAX_NAME_LENGTH)}...`;
  + }
  +
  let topic = rooms[i].topic || '';
  + if (topic.length > MAX_TOPIC_LENGTH) {
  + topic = `${topic.substring(0, MAX_TOPIC_LENGTH)}...`;
  + }
  topic = linkifyString(sanitizeHtml(topic));
  rows.push(
  