hfp_ag_bluez5: Create a hash to store emulators
hfp_ag_bluez5: Store emulator when connect
hfp_ag_bluez5: Remove emulator when disconnect
include: Add ofono_emulator_create_card()
emulator: Add Handsfree Audio Card to emulator
emulator: Register card when establish SLC
hfp_ag_bluez5: Create card for emulator when connect
emulator: Set local and remote address of card
hfp_ag_bluez5: Pass fd to card creation

We can extract local and remote address from the file descriptor.
emulator: Add init and cleanup functions
main: Call emulator init and cleanup functions
phonesim: Include hfp.h
hfp_ag_bluez5: Include hfp.h
hfp: Move HFP versions definitions to hfp.h

hfp.h should store all HFP related definitions.
hfp_ag_bluez5: Remove unused includes
emulator: Add a Card driver for HFP 1.6

This is just the skeleton of a Handsfree Audio Card for the AG side of
HFP 1.6.
emulator: Set card version
hfp_ag_bluez5: Pass HFP version to card creation
hfp_ag_bluez5: Register HFP AG version 1.6
emulator: Add Codec Negotiation feature

This commit adds Codec Negotiation to the emulator's list of features.