Location tracking

Please can you check process.memory().usage for a bit? And does it seem to be writing to the console pretty much all the time?

I've been trying to debug some issues with this, and all the issues I hit seem to be:

• Running out of memory inside the interrupt handling the scan
  
• Filling the output buffer inside the IRQ
  
  

If you look in here in a few minutes: http://www.espruino.com/binaries/travis/bc5039794d1063b2035efbfc0bb674b1c33cd802/

... you should find a substantially more stable build that'll survive even doing something like this where it keeps running out of memory and output buffer space:

NRF.setScan(function(device) {
  Bluetooth.println(JSON.stringify(device));
});