Allow finding Makefile.bsdwrapper1 when obj/.. is not the src tree

As happens when you put obj someplace else and a symlink to it in the
source.
Fixing where we pick up specific man pages so vax can have them

Merging back in lost changes from 1.11 and now reintroduced in 1.21.

http://www.openbsd.org/cgi-bin/cvsweb/src/gnu/usr.bin/perl/Makefile.bsd-wrapper1.diff?r1=1.20;r2=1.21;f=h
Keep the path to the old file when regenerating the man-page list

Because for some files, we "correct" where it comes from so we can have
it on vax and need to keep that.