Espruino 2v18 released

It's new release time - a few nice improvements this time:

General

• JIT compiler supports more language and is now built into all Official Espruino boards (apart from the Original)
  
• OneWire now works reliably on nRF52 alongside Bluetooth (ops are scheduled between Bluetooth transmissions)
  
• STM32 fixed occasional neopixel glitches caused by pin state change
  
• Fix waveform input/output when not done at system start (a regression since 2v13)
  
• Add Serial.flush() to allow us to wait for transmission on a device to finish
  
• Added g.floodFill() method to allow flood fill
  
• Added E.stopEventPropagation() to allow event propagation to be stopped with multiple X.on('...', ...)
  
• Modified E.toString to always return a String (not necessarily flat) - fixes occasion errors in Bangle.js clocks that use it when setting up fonts, and add E.toFlatString for old behaviour
  
• g.asImage() and g.drawImage(gfx) now use palette+transparent fields if they exist in a Graphics object
  
• You can now send advertisements while connected with NRF.setAdvertising({},{whenConnected:true})
  
• Add NRF.on('bond'/'advertising') events
  
• Many other bugfixes for memory/stability/compatibility issues
  
  

Bangle.js 2

• Fixed the 'Ghosting' issue that happened after the welcome message
  
• Switched to proprietary heart rate algorithm which does a much better job when moving around
  
• Now auto-reset compass if it was on while the watch was charging
  
• If a Storage file called '.loading' exists, use that instead of the loading screen - there's now an app to set this up
  
• Ensure overlays are flipped when screen is flipped 180 degrees (eg. left-handed mode) - fixes swipe-on widgets used in some clocks now
  
  

ESP32

• Fixed crashes on reset/load
  
• Enable XON/XOFF flow control (IDE can now not add pauses, so uploads quicker)
  
• Bluetooth UART connection enabled by default
  
• Bluetooth advertising name is now Espruino abcd