This adds the API for putting the AP in Push Button mode, which we'll
need to P2P GO side but may be useful on its own too. A WSC IE is added
to our beacons and probe responses indicating whether the PBC mode is
active.
To limit the number of ap_start parameters, group basic AP config
parameters in the ap_config struct that is passed as a pointer and owned
by the ap_state.
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.
