Use packetbody_t more places.
Adjust invoke_dissector() to have 5 integer arguments, two packetbody_t
capability arguments, and two void capaility arguments to handle all the
print functions I found in a visual audit.
Wrap internal _print functions declared in netdissect.h.
Wrap the majority of remaining dissectors.
Add a few scripts used in wrapping dissectors in case I need to
regenerate the code.