Put print/keyword routines into separate modules; delete attime.c, use

Put print/keyword routines into separate modules; delete attime.c, use
strftime(3) instead; put combination keywords into main keyword list,
sort, delete aliases, and use bsearch(3); don't fail if nlist fails or
devices aren't found.  Whack the manual page for consistency, correctness.

SCCS-vsn: bin/ps/print.c 5.1
SCCS-vsn: bin/ps/nlist.c 5.1
SCCS-vsn: bin/ps/ps.h 5.1
SCCS-vsn: bin/ps/keyword.c 5.1
SCCS-vsn: bin/ps/ps.c 5.31
SCCS-vsn: bin/ps/ps.1 6.9
SCCS-vsn: lib/libc/gen/devname.c 5.9