Rather than have device.c manage the creation/removal of
AP/AdHoc interfaces this new event was introduced. Now
anyone can listen for device events and if the mode changes
handle accordingly. This fixes potential memory leaks
in WSC when switching modes as well.
Now, a user can setup an AP as follows:
- Set device "Mode" to ap (ap interface will appear on bus)
- call "Start()" on AP interface
Issuing "Stop()" on the AP interface will stop and cleanup
the internal AP structures, but the AP interface will remain
up. To shutdown completely the device Mode must be switched
back to station. If the AP interface is running, the Mode can
directly be switched to station without calling Stop; this
has the same effect and will take down the AP interface.