Bug 1084257: Added Bluetooth Core API and I/O

The Core interface wraps calls to bluedroid and adds some additional
checks for consistency.

The I/O code for the Bluetooth Core interface translates request
PDUs to Bluetooth calls, and Bluetooth results to reply PDUs.
Bug 1084257: Added support for the socket-profile interface

This commit adds support for the Socket module. It allows for
implementing services based on OPP.