Easy button to switch between `Working` and `SlideShow` Screen Environments

There was a question here about having a button in a docked cell to switch between the Working and SlideShow environments in Mathematica. In the notebook linked at the bottom there is code to generate a docked cell that allows you to toggle between the Working and SlideShow environments and also allows to to run the Working environments in full screen mode.

There are instructions on how to turn this into a stylesheet. You can download the Mathematica notebook here.