Bug 806003 -  Wait for components ready before enabling airplane mode

This patch will disable and enable the airplane mode switch only when the device is ready to do so.

We check on the following events to determine "Readiness", please let me know if there is a better event to check on, but this was as late as I could find:

geolocation: addObserver('geolocation.enabled')
wifi: WifiManager.onenabled || WifiManager.ondisabled
bluetooth: Bluetooth.ondisabled || Bluetooth.onadapteradded