How to configure iMessages in OS X Yosemite and iOS 8.1 for SMS Forwarding

How to configure iMessages in OS X Yosemite and iOS 8.1 for SMS Forwarding
With the release of OSX Yosemite and iOS 8.1 it is now possible to send and receive SMS via the Messages app in Yosemite and on the iPad. I had to troubleshoot my setup to get SMS Forwarding to work and here is what I found out: Your devices (iPhone, iPad, Mac) need to be ...