Closes#4236
CMake now creates a header file in the build directory under the path "include/Globals.h" which just includes "src/Globals.h" with an absolute path. Then instead of adding "src/" to the include directories, it adds "include/".
#include "Globals.h" still works by including the build generated file and any other src-relative path will not work.
Rename Cavespider.cpp to CaveSpider.cpp
Rename Cavespider.h to CaveSpider.h
Rename Magmacube.cpp to MagmaCube.cpp
Rename Magmacube.h to MagmaCube.h
Rename Zombiepigman.cpp to ZombiePigman.cpp
Rename Zombiepigman.h to ZombiePigman.h