copy arduino/HardwareSerial.* to Serial.*
add: DISABLE_RX to Serial.cpp
remove: ENABLE_SERIAL_LOG_WAIT from GTPowerA6-10 and clones
add: ENABLE_EXPERT_VOLTAGE_CALIBRATION
Merge https://github.com/stawel/cheali-charger

Conflicts:
	src/hardware/GTPowerA6-10-original/cheali-charger-GTPowerA6-10.size
	src/hardware/Turnigy-A-6-10-200W/cheali-charger-Turnigy-A-6-10-200W.size
	src/hardware/Turnigy-Accucel-6-50W-5A/cheali-charger-Turnigy-Accucel-6-50W-5A.size
	src/hardware/Turnigy-MEGA-400Wx2/cheali-charger-Turnigy-MEGA-400Wx2.size
	src/hardware/imaxB6-clone/cheali-charger-imaxB6-clone.size
	src/hardware/imaxB6-original/cheali-charger-imaxB6-original.size