Bug 1029389: Asynchronous starting and stopping of profile managers, r=shuang

Profile managers use the new class |BluetoothProfileResultHandler|
to signal the result of initializing of cleaning up operations to
|BluetoothServiceBluedroid|. |BluetoothServiceBluedroid| proceeds
once all profile handlers have finished.

Future patches will build upon this patch to create completely
asynchronous profile managers.
Bug 1029389: Add result-handler class for Bluetooth Handsfree profile, r=shuang
Bug 1029389: Asynchronous Bluetooth Handsfree init and cleanup methods, r=shuang
Bug 1029389: Asynchronous Bluetooth Handsfree connection handling, r=shuang
Bug 1029389: Asynchronous Bluetooth Handsfree voice-recognition functions, r=shuang
Bug 1029389: Asynchronous |BluetoothHandsfreeInterface::VolumeControl|, r=shuang
Bug 1029389: Asynchronous |BluetoothHandsfreeInterface::DeviceStatusNotification|, r=shuang
Bug 1029389: Asynchronous Bluetooth Handsfree response methods, r=shuang
Bug 1029389: Asynchronous |BluetoothHandsfreeInterface::PhoneStateChange|, r=shuang