first cut for new proc & user structs (still need to put in new vnode calling

first cut for new proc & user structs (still need to put in new vnode calling
convention): get credentials, etc, via proc; u.u_nd, u.u_spare are gone;
purge user.h; remove ../ufs/ from includes; consolidate *nullops();
chown/fchmod use proc's credentials, not file's

SCCS-vsn: sys/ufs/mfs/mfs_vfsops.c 7.18
SCCS-vsn: sys/ufs/mfs/mfs_vnops.c 7.21
SCCS-vsn: sys/ufs/ffs/ffs_alloc.c 7.24
SCCS-vsn: sys/ufs/lfs/lfs_alloc.c 7.24
SCCS-vsn: sys/ufs/ffs/ffs_balloc.c 7.12
SCCS-vsn: sys/ufs/lfs/lfs_balloc.c 7.12
SCCS-vsn: sys/ufs/ffs/ufs_disksubr.c 7.15
SCCS-vsn: sys/ufs/ufs/ufs_disksubr.c 7.15
SCCS-vsn: sys/ufs/ffs/ffs_inode.c 7.38
SCCS-vsn: sys/ufs/ffs/ufs_inode.c 7.38
SCCS-vsn: sys/ufs/lfs/lfs_inode.c 7.38
SCCS-vsn: sys/ufs/ufs/ufs_inode.c 7.38
SCCS-vsn: sys/ufs/ffs/ufs_lockf.c 7.3
SCCS-vsn: sys/ufs/ufs/ufs_lockf.c 7.3
SCCS-vsn: sys/ufs/ffs/ufs_lookup.c 7.28
SCCS-vsn: sys/ufs/ufs/ufs_lookup.c 7.28
SCCS-vsn: sys/ufs/ffs/ufs_quota.c 7.7
SCCS-vsn: sys/ufs/ufs/ufs_quota.c 7.7
SCCS-vsn: sys/ufs/ffs/ffs_vfsops.c 7.51
SCCS-vsn: sys/ufs/ffs/ufs_vfsops.c 7.51
SCCS-vsn: sys/ufs/lfs/lfs_vfsops.c 7.51
SCCS-vsn: sys/ufs/ufs/ufs_vfsops.c 7.51
SCCS-vsn: sys/ufs/ffs/ffs_vnops.c 7.58
SCCS-vsn: sys/ufs/ffs/ufs_vnops.c 7.58
SCCS-vsn: sys/ufs/lfs/lfs_vnops.c 7.58
SCCS-vsn: sys/ufs/ufs/ufs_vnops.c 7.58