Get Line/Sector hit and hit location from a LineAttack

[ZZYZX]

I'd rather put all GZDoom classes under a namespace and require all future mods to use it after some version.
That is, e.g. if ZScript version is 3.4+, then it should be gz::Tracer instead of Tracer if you want to make an instance of it.
Won't solve issues with the existing mods, but probably will fix the future ones and separate user code from engine code once and forever. (remember Grenade?)

[Graf Zahl]

It needs to be a bit more intelligent to avoid problems. The reasons it wasn't done originally is because the type system was written in a way that made namespacing close to impossible and after rewriting the relevant parts to be more flexible I had no time to do it.