Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

- Include rpcv2.h before other NFS includes. That allows nfscbd to
compile.

Code cleanup for nfs4 utilities:

- Mark internal routines as static;
- Eliminate unused parameters where possible, mark __unused for others;
- Remove unused variables;
- Use %jd for int64_t values in printf();
- Add appropriate %d for printf to match its parameter;
- Rename a variable to resolve conflict with revoke(2);

Reviewed by: rmacklem
Tested with: make universe (bugs are mine)

Add two new utilities and two new daemons to /usr/src/usr.sbin that
are specifically used by the experimental nfsv4 subsystem.
nfscbd - The NFSv4 client callback daemon.
nfsuserd - The NFSv4 daemon that maps between user and group name
and their corresponding uid/gid numbers.
nfsdumpstate - A utility that dumps out the NFSv4 Open/Lock state.
nfsrevoke - Administratively revokes an NFSv4 client, releasing all
NFSv4 Open/Lock state it holds on the server.

Approved by: kib (mentor)