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

platform/android/jni_utils.h

@@ -32,8 +32,8 @@
 #define JNI_UTILS_H
 
 #include "string_android.h"
-#include <core/engine.h>
-#include <core/variant.h>
+#include <core/config/engine.h>
+#include <core/variant/variant.h>
 #include <jni.h>
 
 struct jvalret {