Fix the NFS client/server so that it actually uses the 64bit ino_t filenos.

The code still doesn't use d_off. That will come in a future commit.
The code also removes the checks for servers returning a fileno that
doesn't fit in 32bits, since that should work ok now.
Bump __FreeBSD_version since this patch changes the interface between
the NFS kernel modules.

Reviewed by: kib