Bug 1027030: Wrap Bluedroid interfaces in classes, r=shuang

This patch adds classes around all Bluedroid interfaces that are
currently used by Gecko. These are Core, Socket, Handsfree, A2DP,
and AVRCP.

All arguments and return values are still Bluedroid types and
constants. Future patches will convert them to interface-neutral
artifacts.
Bug 1027030: Convert Bluetooth to use Bluedroid wrappers, r=shuang

This patch converts the Bluedroid backend to use the wrapper
classes. The affected interfaces are Core, Sockets, Handsfree,
A2DP, and AVRCP.