Fix review problems

- removed superfluous position and classes
- fixed compact view
- fixed event list summary avatar and text overlap
- fixed a problem where the mention list refuses to load.

src/components/views/rooms/EventTile.js

@@ -659,8 +659,6 @@ export default createReactClass({
         const classes = classNames({
             mx_EventTile_bubbleContainer: isBubbleMessage,
             mx_EventTile: true,
-            mx_EventTile_irc: this.props.useIRCLayout,
-            mx_EventTile_group: !this.props.useIRCLayout,
             mx_EventTile_isEditing: isEditing,
             mx_EventTile_info: isInfoMessage,
             mx_EventTile_12hr: this.props.isTwelveHour,