Fixes bug caused introduced when adding the offset (temps only reading 0)

This will allow any plugin to listen for a notification and respond accordingly.

-Brew Steps added
-Clean AddOn Dialog

lines 138 and 144 were changed to f.cooler

I've noticed that sensor values are being handled as integers by this function, which was causing poor performance of the PIDArduino logic and another logic plugin I am testing.  I have changed the type to float, and now logic controllers can receive more accurate temperature values.

- Method actor_power added to set the power without switching
- Method timer_remaining added to get the remaining time of a timer

Correct datatypes for def F automode to work

- Kettle Controller Fix
- Remove SQL Alchemie

Closes https://github.com/Manuel83/craftbeerpi3/issues/7