telephony: don't parse request message when not needed

Open-WebOS-DCO-1.0-Signed-Off-By: Simon Busch <morphis@gravedo.de>
wan: implement status notification API

Open-WebOS-DCO-1.0-Signed-Off-By: Simon Busch <morphis@gravedo.de>
ofono: implement basic functionality for the wan service functionality

Signed-off-by: Simon Busch <morphis@gravedo.de>