Import spread-4.3.0 as wip/spread4.

Spread is a group communication system that provides a number of
messaging services to applications. These services can then be used
by applications to make it easy to write full-featured reliable
groupware, distributed servers, client-server applications, chat
and news services, and many other networked enabled tools.
added ruby-cabin
Snapshot 20131013.
flex is needed of course
Bump version 0.16.2 (as noted on wip/TODO).
Many things to be improved, but at least packaged on NetBSD/amd64 6.1.1
with default options. PLIST variations by options are not checked yet.
Put distfile up on ftp.netbsd.org