Bug 1072811 - [Bluetooth] BluetoothHelper APIv2 support

* patch bluetooth_helper
* revice bluetooth mockup
* add uitest/HW/bluetooth for demo
The above two lines are only working on API v1. It should be put in scope `else`(v1).

If we also want to reach the time for re-getting adapter while receiving `enabled` state, we have to watch `state` attribute via `mozBluetooth.defaultAdapter.onattributechanged` event.

And the `adapteradded` event which we have handled via `mozBluetooth.onattributechanged`.

Ref: https://wiki.mozilla.org/B2G/Bluetooth/WebBluetooth-v2/BluetoothAdapter#onattributechanged