Add some more data.

- Changed Min/MaxModulation to  Min/MaxPumpModulation
- Added Min/Maxmodulation (this is the heater)
- Added Desinfectiontemperature
- Added MasterHeatingSwitch / MasterWWSwitch for incoming data processing
Added SensorPumpenModulation and SensorWaermetauscherTemp database sensors.

The first is needed to see if the pump size is correctly chosen, and the latter
is very useful to track down errors like 0Y 277 (this temp triggers it when >95 deg.).
More additions and enhancements.

- burner/pumpmodulation consistently named
- parseEnum() helper function for easy parsing of Enum values
- a bunch of new data parsing functions:
  parseUBAMaintenanceSettingsMessage(),
  parseUBAMaintenanceStatusMessage(),
  parseUBAMaintenanceStatusMessage()
- stubs for parseRCSystemParameterMessage(), parseRCHKOpmodeMessage(), parseRCHKScheduleMessage() - follow soon.
Introduce an integer reading type for actual integers.

Otherwise, printing might switch to exponential representation for large
values.
Use a single value for maintenance date.
Fix system time format.