Properly handle residual count in Data-In PDUs with S bit set.

Approved by:	re (gjb)
Sponsored by:	FreeBSD Foundation
By popular demand, move freebsd-version(1) from /libexec to /bin.

Approved by:	re (gjb)
Handle the cases where NULL is passed as cap_rightsp to the
filestat_new_entry() function.

Reported by:	Alex Kozlov <spam@rm-rf.kiev.ua>
Approved by:	re (gjb)