This is silly. The libraries used have absolutely nothing to do with
"Linux". They're POSIX standard libraries, and will work just as
well on Mac OS X and BSD. The actual code might need to be replaced,
but in any case, this isn't something to limit to "Linux" systems.
In most cases, this has also resulted in limits being lifted. (The
only place I haven't done this is for planets in intermission.cpp,
but I think I'll take away that 10-planet limit as well.)
This is silly. I can see that someone decided to restrict targeting
to one ship as a difficulty setting, but that's not a very good way
to achieve different levels of difficulty.
Also added more music and slowed down RE.ogg.