Explicitly use the iterator approach.

Why should iterators be used for the buttons to erase anyway?

src/InputFilter.cpp

@@ -274,7 +274,7 @@ void InputFilter::Update( float fDeltaTime )
 
 	vector<ButtonStateMap::iterator> ButtonsToErase;
 
-	FOREACHM( DeviceButtonPair, ButtonState, g_ButtonStates, b )
+	for( map<DeviceButtonPair, ButtonState>::iterator b = g_ButtonStates.begin(); b != g_ButtonStates.end(); ++b )
 	{
 		di.device = b->first.device;
 		di.button = b->first.button;