Better integrate AC config

[mschmiedel]

What is the feature?

Normally, it does not make sense to use the AC in winter for cooling, nor the radiator heater in summer for heating. This can be improved easily.

Description

Right now, there is one external temperature to turn off heating. This should work for heating no matter if the source is AC or Radiator.
Add another similar setting that states "turn off cooling if outside temperature is under X". This should keep the AC from cooling if external temperature is under a certain level.

Additional Information

This can help use the settings in a way more efficient way.