Having synchronous API is wrong, or at least questionable.
Granted, libnm isn't currently very good about the exact order
of things to happen. However synchronous API by design delays events
while waiting for the response and hence messes up the ordering.

Maybe synchronous API should not be added to libnm.

Or at least, if we have synchronous API, we certainly need an asynchrnous
variant as well (which is still missing).

As synchronous API is not preferred, it should also be named
nm_some_thing_sync(), accompanied by nm_some_thing() and
nm_some_thing_finish(). The name for the synchronous method should be the
odd one and we shouldn't have an nm_some_thing_async(). Yes, libnm is not
consistend about that.

I am going to drop this API for the moment.