rlocs: Move debug outputter to common code
util: Remove some debugging comments
packet: move some common code out of wrapper.c and util.c
Reorganise so we have wrapper, unwraper and hide-eid.

unwrapper and hide-eid don't work yet, of course.
This gets us to the point of seemingly being able to wrap and unwrap IPv4

Remarkably hard to test this on a single computer