From library release notes:
- Added beacon transmitter support for qualified Android 5.x devices.
- Added fast, low-power background scanning support for devices with Android 5.x BLE APIs
- Execute scan processing in a ThreadPool so user app AsyncTask execution doesn't accidentally pause scanning.
- Fix bug causing NaN to sometimes appear in distance estimates
- Fix bug causing secondary beacon fields to not update after first detection
- Wake up from deep sleep to continue scanning
- Throw an exception if service not configured properly in AndroidManfiest.xml
