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/io/file_access_pack.h

@@ -31,11 +31,11 @@
 #ifndef FILE_ACCESS_PACK_H
 #define FILE_ACCESS_PACK_H
 
-#include "core/list.h"
-#include "core/map.h"
 #include "core/os/dir_access.h"
 #include "core/os/file_access.h"
-#include "core/print_string.h"
+#include "core/string/print_string.h"
+#include "core/templates/list.h"
+#include "core/templates/map.h"
 
 // Godot's packed file magic header ("GDPC" in ASCII).
 #define PACK_HEADER_MAGIC 0x43504447