Reorganized core/ directory, it was too fatty already

-Removed FuncRef, since Callable makes it obsolete
-Removed int_types.h as its obsolete in c++11+
-Changed color names code

servers/rendering/rendering_server_wrap_mt.cpp

@@ -29,8 +29,8 @@
 /*************************************************************************/
 
 #include "rendering_server_wrap_mt.h"
+#include "core/config/project_settings.h"
 #include "core/os/os.h"
-#include "core/project_settings.h"
 #include "servers/display_server.h"
 
 void RenderingServerWrapMT::thread_exit() {