"Clicker" enabled start-demo.ps1

I often do presentations on or about PowerShell, as most presenters I use Start-Demo.ps1 to make life easier and avoid spelling misstakes, slow typing etc. What I have done are just some very small alterations to allow me to use my clicker to advance and back-up in my demos. I use a Targus clicker and I do not know if it works towards other brands but see below to download the script. Since a clicker is quite limited in the functionality it provides (forward, back and blank) I choose just to remove the other functions as they are not needed when doing presentations.