Bluetooth UART on ESP32

@wilberforce, I've UART running with my Android phone.
@Gordon, testing the same with Windows is a desaster.
There is nothing I can replicate. Problems occur following a kind of randomizing.
Problems like:

• BLE scanner shows all boards, but admin page shows only a few of them.
  
• sometimes ESP32 is not recognized, sometimes puck.js is not recognized
  
• testing with Chrome browser tells "Bluetooth Adapter not available", from time to time
  
• sometimes WebIDE recognizes boards (even Puck.js), but does not connect
  
• and some others where I don't even know how to describe
  
  

My priority right now is to add enable/disable for Bluetooth which saves about 2000 jsVars.
Once this is done, next step will be to add UART, at least for Android clients
Last not least, Windows will get a new try. BTW, feedback from ESP32Forum to Windows was poor, and misleading. Nothing from an Espruino guy.