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

editor/progress_dialog.cpp

@@ -30,7 +30,7 @@
 
 #include "progress_dialog.h"
 
-#include "core/message_queue.h"
+#include "core/object/message_queue.h"
 #include "core/os/os.h"
 #include "editor_scale.h"
 #include "main/main.h"