Enhance audit logs to support SysV message queues

Enhance audit logs to support SysV message queues

Adds support for sysv message queues for fileserver audit logs. This
also organizes the audit log code into various 'interfaces', of which
there are two: the original 'file' interface, and the 'sysvmq' interface
that this adds. The interface is configurable at runtime with the
-audit-interface switch.

FIXES 124674

Reviewed-on: http://gerrit.openafs.org/82
Tested-by: Andrew Deason <adeason@sinenomine.net>
Tested-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Derrick Brashear <shadow@dementia.org>