[new and wip]: audio/csound

Hi,

here's a quick hack to port csound to OpenBSD. Category "It compiles,
let's ship it", but at least I was able to create WAVs from the
examples included in the sources ('xanadu' and 'trapped').

I don't want any ok's for now, but I'd really appreciate tests and
comments on this, especially from people currently running csound
on other systems.

There's no native audio or midi support, audio is done with pulseaudio
(or just writing the output to a file).

For those who have no idea what this thing is:

Csound is a sound and music computing system that has its roots in
the earliest of computer software, the MUSIC-N series by Max Mathews.
Csound was originally released in 1986 by Barry Vercoe and it has
been a part of the computer music world since. Today's Csound works
on desktop, mobile, embedded, server, and web platforms and powers
music software and music-making for musicians around the world.

Ciao,
Kili

ps: the code base of csound is *old*, there's a mess of #ifdef's,
maybe for systems that don't exist any longer, and there are "fixes"
done in the wrong place (like the first chunk of
patches/patch-Top_csound_c). So don't look at the code unless you're
brave. I'll submit the patches to upstream when this port is good
enough.