... instead of manually handling method calls, properties, automatic timeouts, etc..

While going through the patch to add an extra 'as' parameter to RefreshDB (bug 728878), I realized that we don't need to deal with so much detail about acquiring the bus, registering objects on it, unwrapping the parameters from the GVariant, etc.. This is only going to get more complicated as the API evolves (eg., if we add a signal in the future).

I think that using a gdbus-codegen-ed GDBusInterfaceSkeleton and GApplication makes things easier by reducing some of these details and generating the corresponding C API from the XML for us. If not anything else, it makes it more consistent with all the code out there that is already using GApplication and gdbus-codegen.