It is probably rare that a disconnect should fail but if it happens the
device->state is not returned to CONNECTED and I'm not sure if it should
be, so the ConnectedNetwork property and other bits should probably be
reset at the start of the disconnection instead of at the end.
Also check if state is CONNECTED before calling network_disconnected
because network_connected may have not been called yet.
The eapol state machine parameters are now built inside device.c when
the network connection is attempted. The reason is that the device
object knows about network settings, wiphy constraints and should
contain the main 'management' logic.
netdev now manages the actual low-level process of building association
messages, detecting authentication events, etc.
Turn netdev watches into device watches. The intent is to refactor out
netdev specific details into its own class and move device specific
logic into device.c away from wiphy.c
