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

core/input/input.cpp

@@ -30,10 +30,10 @@
 
 #include "input.h"
 
+#include "core/config/project_settings.h"
 #include "core/input/default_controller_mappings.h"
 #include "core/input/input_map.h"
 #include "core/os/os.h"
-#include "core/project_settings.h"
 
 #ifdef TOOLS_ENABLED
 #include "editor/editor_settings.h"