4.1.1

Summary

This is a patch release to fix several minor issues and two regressions in the 4.1.0 release.

Changes

• #6711 - Correct path to cleancss (@tschaub)
• #6728 - Fix tissot examples docs (@fredj)
• #6732 - Use firefox < 53 in travis (@fredj)
• #6741 - Allow user selection in overlay container (@fredj)
• #6755 - Add missing goog.require (@fredj)