Support GATT services over BR/EDR.

Preview at https://rawgit.com/WebBluetoothCG/web-bluetooth/support-bredr/index.html

@armansito
I think this behavior is OK. Once we reconnect to a device, if we're not bonded then the UA must perform service discovery again and based on that it can update the UUID list if the service was removed. If the device IS bonded, then we should receive an immediate Service Changed indication upon connection.