audio-settings: Fix unneeded async for GetProperties

GetProperties method call for Audio settings returns the reply in the
same iteraction, it doesn't need to be asynchronous.
include: Add handsfree card create / remove API
handsfree-audio: Implement card create / remove
include: Add handsfree card register method
handsfree-audio: Don't hardcode '/' path

Use OFONO_MANAGER_PATH instead
handsfree-audio: Add skeleton D-Bus registration

For HandsfreeAudioCard objects
handsfree-audio: Unregister from DBus on removal
handsfree-audio: Implement card GetProperties
handsfree-audio: Implement the GetCards method
handsfree-audio: Implement CardAdded signal
handsfree-audio: Impelement CardRemoved signal
bluez4: Increase Bluez 4 D-Bus timeouts to 60 seconds

RequestAuthorization method call may trigger pairing and/or pop up a
dialog in the remote device to which the user needs to react. Thus
increase D-Bus timeouts to 60 seconds for the Bluez 4 plugin.
doc: Add possible handsfree-audio API errors

This patch adds possible errors that can be returned by Register and
Unregister methods of the Manager interface.
handsfree-audio: properly increment next_card_id
bluez5: Move ref / unref handsfree audio

This commit moves the ref / unref to hfp_hf_bluez5 to make
bluez5 more generic and reusable.
bluez5: Add role parameter to bt_register_profile

This commit allows asymmetric profiles that do not have UUIDs
available to uniquely identify each role specify which role is
been registered.
hfp_hf_bluez5: Change register profile call
hfp_ag_bluez5: Change register profile call
dundee: Rename dundee BlueZ 4 support

The BlueZ 4 support file for dundee has now been renamed to
bluez4.c to make it easier to add a BlueZ 5 support file.
dundee: Start BlueZ 5 support

This patch adds the BlueZ 5 support file for dundee.