Stop the Avatar classes setting properties on <span>s

React apparently now checks the properties which are set on DOM elements, and
grumbles noisily about unexpected ones. Update BaseAvatar and RoomAvatar so
that they don't set unrelated properties on the DOM elements.

src/components/views/avatars/RoomAvatar.js

@@ -126,11 +126,13 @@ module.exports = React.createClass({
     render: function() {
         var BaseAvatar = sdk.getComponent("avatars.BaseAvatar");
 
-        var roomName = this.props.room ? this.props.room.name : this.props.oobData.name;
+        var {room, oobData, ...otherProps} = this.props;
+
+        var roomName = room ? room.name : oobData.name;
 
         return (
-            <BaseAvatar {...this.props} name={roomName}
-                idName={this.props.room ? this.props.room.roomId : null}
+            <BaseAvatar {...otherProps} name={roomName}
+                idName={room ? room.roomId : null}
                 urls={this.state.urls} />
         );
     }