message: Hide tooltips with CSS when they aren't visible
  Fixes
diff: @@ -100,7 +100,9 @@ module.exports = createReactClass({
  const parent = ReactDOM.findDOMNode(this).parentNode;
  let style = {};
  style = this._updatePosition(style);
  - style.display = "block";
  + // Hide the entire container when not visible. This prevents flashing of the tooltip
  + // if it is not meant to be visible on first mount.
  + style.display = this.props.visible ? "block" : "none";
  const tooltipClasses = classNames("mx_Tooltip", this.props.tooltipClassName, {
  "mx_Tooltip_visible": this.props.visible,
  