ioquake3 breaks compatibility with id Tech 3

[Tim Angus]

Ryan C. Gordon wrote:
> I don't think libgthread.so is an SDL dependency, unless something like 
> libesound is pulling it in...in which case, SDL can and should be built 
> to dlopen() those libraries at runtime.

Yeah, it wasn't SDL pulling in libgthread itself, but another library. I 
did a quick check and I can't find what it was. It was 2 years ago 
though, so lots of things could have changed in the mean time.