zm_origin_b6 addon

This is the science lab where it all began. Experiments went horribly wrong, turning humans into blood thirsty monsters. A group of 15 survivors have gone to the labs to stop the experiments once and for all. This is the first beta, there're hardly any bugs but I'll improve the map in the future. Note: This is for the normal Zombie Master mod, ModDB didn't have the mod on their list. -_-