Fix Filename type in attribute struct to support unicode strings

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3776 dfc29bdd-3216-0410-991c-e03cc46cb475

include/IAttributeExchangingObject.h

@@ -43,7 +43,7 @@ struct SAttributeReadWriteOptions
 	s32 Flags;
 
 	//! Optional filename
-	const c8* Filename;
+	const fschar_t* Filename;
 };