rt_sqrt.c: I've managed to replace the old FixedSqrtHP function with sqrt, thanks to Samuel Thibault who explained to me that this function was useful back in the days to make the game run on FPU-less computers. The fact that it multiply the actual square root and store it into a long allows the program to avoid using a float, which was very costly in terms of performances back then, and still keep a high precision.