Thermostat Beta Additions

This code is definitely still in development, but this should allow some users with different thermostats to test out how it works with C vs F temps.   My thermostat pushes all of the updates, but others may not work the same way.   

You'll notice I was going to change how the temp. sensor works, but I like how you do it better-  convert it to C and then let the UI decide how to display it based on a configuration param.

In any case, feel free to modify if you see anything that doesn't conform to your conventions.  

Once I figured out the system, I really liked how you coded everything-  very flexible and extendable!