message: don't hide empty sections that have a (+) button
diff: @@ -526,8 +526,9 @@ module.exports = React.createClass({
  props = Object.assign({}, defaultProps, props);
  const isLast = i === subListsProps.length - 1;
  const len = props.list.length + (props.extraTiles ? props.extraTiles.length : 0);
  - if (!len) {
  - return components; //dont render
  + // empty and no add button? dont render
  + if (!len && !props.onAddRoom) {
  + return components;
  }
  const {key, label, ... otherProps} = props;
  const chosenKey = key || label;
  