volscan: print vnode metadata information

volscan program to print vnode meta-data in a grep/awk/perl friendly
format. Optionally, find the paths of each vnode relative to the volume
root.  Access control list data can be reported, and are listed as one
access entry per line. Mount point information can be shown to which
volumes are mounted from given volumes.

The path lookup code originally written by Tom Keiser.

1.6 note: The 1.6 libcmd lacks parameter offsets, so this commit
instead splits the param enums into volinfo_parm_t and volscan_parm_t,
and just uses the regular cmd_AddParm to put the parameters in the
same place as the enums. In addition, rx queues are used instead of
opr queues, since opr queues do not exist in 1.6.

Reviewed-on: http://gerrit.openafs.org/5102
Reviewed-by: Derrick Brashear <shadow@dementix.org>
Tested-by: Derrick Brashear <shadow@dementix.org>
(cherry picked from commit a08c3207255756c825ab69a19e04f79dd879c646)

Change-Id: Icd7c572d09fd5a5e82bd8a1d09c6fbbe229b6b1c
Reviewed-on: http://gerrit.openafs.org/11267
Tested-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>