seems that my last post didn't make it through. That's good
since the diff itself didn't covered the renaming of
pg_user.h to pg_shadow.h and it's new content.
Here it's again. The complete regression test passwd with
only some float diffs. createuser and destroyuser work.
pg_shadow cannot be read by ordinary user.
tree "non-PORTNAME" dependent. Technically, anything that is PORTNAME
dependent should be able to be derived at compile time, through configure
or through gcc