This patch fixes how the NFS client handles full NFS version 3 64-bit fileids.

Previously, messages of the form:
NFS3 LOOKUP: directory attributes from <servername> are of the wrong dir

would appear on the console when traversing an NFS version 3 server filesystem
that generated greater than 32-bit file ids.  This patch stores the full 64-bit
fileid (as specified by protocol) and uses that actual value to compare.

This patch also fixes a potential issue with NFS version 3 memory mapped 
files that can lead to a system panic.

This panic can manifest itself in a number of ways.  Example panics are:

 pmap_update_send: missing ack from cpu 3
 panic (cpu 1): tb_shoot ack timeout

 trap: invalid memory read access from kernel mode

and on SCFS members:

 panic (cpu 0): cmn_err: CE_PANIC: elan0: heartbeat pacemaker - flatlined ....


Fixes a possible race with m_freem() and clntkudp_destroy which could
lead to a mixed up mbuf chain.

Change to the NFS client to decouple it from the networking driver's
processing, specifically from the delay to free transmitted buffers.




