[quake2] Full game installer

[Vincent S. Cojot]

In Reply to Zakk,

> See my other reply for why it's probably not going into CVS.
> I thought people might like the ability to choose between the two
> binaries.

Yes I do! :) And moreover, sdlquake2 is the only binary that has sound on
some other platforms (sparc/Solaris, perhaps sparc/Linux too) since SDL
usually  gets ported before the quake2 native sound driver..Please keep
sdlquake2. :)

Vincent