* Centralite specific control seq of operation
* Remove Fan safeguards
* Split hvac_action property.
* Refactor hvac_action property.
Current hvac_action logic is Zen Within thermostat specific and differs
a bit from ZCL specs. Implement it as a separate class.
* Refactor hvac_action property for default thermostat
Follow more closely ZCL specs in parsing hvac state of the thermostat.