changes for whiteouts and union filesystem

changes for whiteouts and union filesystem

SCCS-vsn: bin/ls/ls.c 8.6
SCCS-vsn: bin/ls/util.c 8.4
SCCS-vsn: bin/ls/print.c 8.5
SCCS-vsn: bin/ls/stat_flags.c 8.2
SCCS-vsn: bin/rm/rm.c 8.6
SCCS-vsn: include/dirent.h 8.2
SCCS-vsn: include/fts.h 8.2
SCCS-vsn: include/unistd.h 8.11
SCCS-vsn: lib/libc/gen/opendir.c 8.5
SCCS-vsn: lib/libc/gen/fts.c 8.5
SCCS-vsn: lib/libc/gen/readdir.c 8.2
SCCS-vsn: lib/libc/sys/chflags.2 8.2
SCCS-vsn: lib/libc/sys/Makefile.inc 8.2
SCCS-vsn: lib/libc/sys/undelete.2 8.2
SCCS-vsn: lib/libc/string/strmode.c 8.2
SCCS-vsn: usr.bin/chflags/chflags.1 8.3
SCCS-vsn: usr.bin/find/find.c 8.4
SCCS-vsn: usr.bin/find/function.c 8.7
SCCS-vsn: sbin/fsck/pass2.c 8.3
SCCS-vsn: sys/ufs/ffs/ffs_vnops.c 8.9
SCCS-vsn: sys/ufs/ufs/ufs_lookup.c 8.8
SCCS-vsn: sys/ufs/ufs/ufs_vnops.c 8.12
SCCS-vsn: sys/ufs/ufs/ufs_extern.h 8.5
SCCS-vsn: sys/ufs/lfs/lfs_vnops.c 8.7
SCCS-vsn: sys/ufs/mfs/mfs_vnops.c 8.5
SCCS-vsn: sys/kern/vfs_syscalls.c 8.19
SCCS-vsn: sys/miscfs/union/union.h 8.7
SCCS-vsn: sys/miscfs/union/union_vnops.c 8.19
SCCS-vsn: sys/miscfs/union/union_vfsops.c 8.12
SCCS-vsn: sys/miscfs/union/union_subr.c 8.12
SCCS-vsn: sys/sys/namei.h 8.3
SCCS-vsn: sys/sys/vnode.h 8.8