TSAGE: Fix compilation on NDS.

It is not safe to assume one can construct a va_list by using NULL. Instead I
created a temporary (uninitialized!) dummy, which is passed in the call to the
Action::attached implementation. I added a TODO to resolve this temporary hack.

engines/tsage/converse.cpp

@@ -320,7 +320,12 @@ void SequenceManager::attached(EventHandler *newOwner, EventHandler *fmt, va_lis
 	}
 
 	setup();
-	Action::attached(newOwner, fmt, NULL);
+	// TODO: This is not particulary nice, since dummy is uninitialized.
+	// Since the default Action implementation does not access the va_list
+	// parameter it should be fine though. Still it would be nice to find
+	// a better solution to this.
+	va_list dummy;
+	Action::attached(newOwner, fmt, dummy);
 }
 
 /**