MKCATPAGES and MANINSTALL.

[Steven Drake <sbd%NetBSD.org@localhost>]

Having these two variables set with the wrong values caused a bulk build I
started on the weekend to fail to build 99.9% of packages! 
(checkperms failed to build if you where wondering.)

While the issue has probably been fixed with by two commits I just made, 
I think they should be set the 'right' values in bsd.prefs.mk rather than
using the setting that comes from mk.conf or bsd.own.mk.

-- 
Steven