Add logging level for hardware

[jsiegmund]

I'd like a logging level setting to be added for (all) hardware added to Domoticz. Reason for this is already mentioned in the following thread: http://www.domoticz.com/forum/viewtopic.php?t=18783. The P1 hardware entry is very noisy, it adds a lot of logging in the Info category. It would be nice if one could dial down such devices a bit by selecting a logging level. Selecting 'Warning' or 'Error' would make sure only messages of that level end up in the logs. This makes the logs more readable.