dundee: Initial skeleton for Bluez 5 support
dundee: (un)registering of bluetooth devices

Now we automatically register and unregister bluetooth devices
that implement DUN_GW.
dundee: property_changed implemented
dundee: creation of dundee_device structures
dundee: Add BlueZ Profile handler

This patch declares the external HFP Profile handler. It contains the
initial implementation of the D-Bus Profile1 interface and methods
responsible for handling Bluetooth connections.