new files for FreeBSD packaging at 1.6.0pre3

new files for FreeBSD packaging at 1.6.0pre3

Packaging for use with FreeBSD's Ports Collection.
The directory layout is flattened, and a couple of files that do not
make sense here are not included.
The afsd rc script lives in packaging/ as it is not runnable in
its committed form, it requires variable substitution that occurs
at install-time from the Ports Collection.

Reviewed-on: http://gerrit.openafs.org/4351
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 7b4da89c8ed266959ec8d3ae4f6627b096206dee)

Change-Id: I0051b9d609736fc172a7c3fefd23cb910b4543e6
Reviewed-on: http://gerrit.openafs.org/4355
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>