* add: update DEBUG_THERMOSTAT to only control the virtual switch
Also, debug output is still generated but end user can control this debug level 3
* add: debug output of main controller parameters when thermostat enabled
Also, add units for debug outputs added to make them more intelligible
* Update xdrv_39_thermostat.ino
* add: debug message when sensor is detected as not alive
fix: display thermostat number in debug messages
* add: log message prefix string for thermostat
* Update xdrv_39_thermostat.ino
fix: typos in comments
add: debug messages
* add: debug prefix for thermostat
* add: debug prefix added to output lines
* fix: comment typos and small grammatical changes for clarity
* add: debug prefix 'THE' added to debug output
* add: display PID status and key info on web output
* fix: remove extraneous comments that included unused code fragments
* add: local sensor handling improvements
add: define a local sensor name
add: define the local sensor measurement parameter
add: limit sensor not seen error message to every 60 seconds to avoid flooding the logs
add: include interval since which sensor data was last updated
fix: properly update the maximum interval time so missing sensor data is properly alerted
* Update xdrv_49_pid.ino