* amd/ops_nfs.c (nfs_init): declare as static to match forward

* amd/ops_nfs.c (nfs_init): declare as static to match forward
definition at top of file.

* conf/nfs_prot/nfs_prot_{hpux11, netbsd1_4,openbsd,aix5_2}.h:
added missing definitions for LOOKUP3res, diropargs3, etc.

* libamu/xdr_func.c (xdr_LOOKUP3res, xdr_am_nfs_fh3),
libamu/mount_fs.c (compute_nfs_args), amd/ops_nfs.c
(got_nfs_fh_mount, got_nfs_fh_webnfs, prime_nfs_fhandle_cache,
webnfs_lookup), amd/amfs_host.c (fetch_fhandle): Attempt to
cleanup some inconsistencies with how we treat NFSv3 file handles.
Whenever we need to get data out of a filehandle given to us, we
assume that it uses the OS's native fhandle structure
(often struct nfs_fh3).  When we store the fhandle data for our
own use, however, we store it in one of two ways.  The first, is
that we use the system's default nfs_fh3 structure; the second is
that we define out own struct am_nfs_fh3 in nfs_prot.h (and go
through an elaborate autoconf song-and-dance to "discover" it as a
native fh3 handle structure).  It appears that we do the latter,
instead of using the system's default fhandle structure, simply to
avoid extra malloc's and free's, because whereas nfsv2's fhandle
structure is a simple 32-byte buffer, nfsv3's fhandle structures
often just define a "char *" for the fhandle data, and the caller
must malloc/free the space inside as needed.  Our code was never
written with constructor/destructor callbacks for these nfsv3
filehandles.  Moreover, we carefully wrote our own am_nfs_fh3
structure so IT JUST SO HAPPENS to align with most (hopefully all)
of the fhandle structures for v3: first four bytes are the length
fields and the next four bytes are the fhandle data.  Sigh.
Having this inconsistent use of v3 filehandles can be a real bear,
because we simply cannot avoid using the system's default fhandle
structure indirectly, through things like diropargs3 in
xdr_diropargs3(), which has inside of it a reference to the
system's default nfs_fh3 structure.  ANYWAY, the current fix I've
come up with is to generalize the way we dereference field names
within the nfs_fh3 structure (whether ours or the system's) and
the same for the system's LOOKUP3res structure.  I'm not pleased
with this fix; I'd rather we don't use our own am_nfs_fh3
structure at all.

* libamu/xdr_func.c (xdr_am_nfs_fh3): always definine this
function if we have NFS3, because we often use our own,
incompatible am_nfs_fh3 structure.

* include/am_xdr_func.h: We cannot use the native system's
xdr_nfs_fh3 because we are defining our own incompatible
am_hfs_fh3 structure for some systems.

* include/am_xdr_func.h: Define default values for field names of
struct nfs_fh3 and LOOKUP3res.

* doc/am-utils.texi (debug_options Parameter): minor typo fixed.

* conf/nfs_prot/nfs_prot_freebsd3.h: FreeBSD uses different fields
names for struct nfs_fh3 and LOOKUP3res, so override the default
names here.

* configure.in: AMU_CHECK_FS_MNTENT(nfs3) test before
AMU_STRUCT_NFS_FH3, because the latter depends on the former.

* amd/ops_nfs.c (prime_nfs_fhandle_cache): add {} to disambiguate
and clarify if-the-else clauses.