Updated Android app to better deal with blue wire comms situations, also added warning of limited
control when an OEM controller is in the mix, disabling the temperature and fixed/thermo modes.
Now using SENSE line from HC-05 to detect a client is connected.
Runs with either sort of HC-05 module, provided the 5 pin regulator style is set to 9600 data mode.
Removed #ifdef BLUETOOTH from .ino file, Bluetooth functions report now anyway with/without client.
Changed "USB" to "DebugPort"
Tidy up of blue wire data frames and passing about by reference instead of just the data buffer.
Added AppInventor application
Changed Tx headers to [OEM] and [BTC] for the OEM controller and this Bluetooth controller.
Added #ifdefs to accomodate Mega and ESP32.
Built and tested on ESP32, Serial1 talks to heater OK using standard pin numbering :-)
If found, it parrots the settings, but allows on/off commands to be inserted by a user.
If no other controller detected, it falls back and delivers our settings each second.
Currently reports all packets to USB, but will move onto Bluetooth delivery of heater data soon.
