A new value for NM80211Mode is introduced (NM_802_11_MODE_AP) and the
new mode is passed to wpa_supplicant analogous to adhoc-mode.
The places which need to know the interface mode have been extended to
handle the new mode.
If the configuration does not contain a fixed frequency, a channel is
selected the same way as with adhoc-mode before.
- the first uses dbus-glib and D-Bus "NameOwnerChanged" signal directly
- the second uses GIO's g_bus_watch_name()
- the third uses Qt and QDBusServiceWatcher class
