Bug 1072811 - [Bluetooth] BluetoothHelper APIv2 support

* patch bluetooth_helper
* revice bluetooth mockup
* add uitest/HW/bluetooth for demo
The event name is revised in version 2. So, it should be `_bluetooth.onadapteradded`.

Ref: https://wiki.mozilla.org/B2G/Bluetooth/WebBluetooth-v2/BluetoothManager#onadapteradded