Enable BT use for Arduino Mega (#718)

* Enable BT use for Arduino boards

by adding a ArduinoSTL library

* Update doc

platformio.ini

@@ -101,6 +101,7 @@ dallastemperature = DallasTemperature
 m5stickc = M5StickC@0.2.0
 m5stack = M5Stack@0.3.0
 smartrc-cc1101-driver-lib = SmartRC-CC1101-Driver-Lib@2.3.5
+stl = https://github.com/mike-matera/ArduinoSTL.git#7411816
 
 [env]
 framework = arduino
@@ -679,13 +680,14 @@ lib_deps =
   ${libraries.onewire}
   ${libraries.dallastemperature}
   ${libraries.rfWeatherStation}
+  ${libraries.stl}
 build_flags =
   ${com-arduino.build_flags}
   '-DZgatewayRF="RF"'
   '-DZgatewayRF="RF315"'
   '-DZgatewayRF2="RF2"'
   '-DZgatewayIR="IR"'
-  ;'-DZgatewayBT="BT"'
+  '-DZgatewayBT="BT"'
   '-DZactuatorONOFF="ONOFF"'
   '-DZactuatorFASTLED="FASTLED"'
   '-DZsensorINA226="INA226"'