Added selected in button class

Basically active, it will probably be renamed

ImageButtonInstance.cpp

@@ -49,6 +49,7 @@ ImageButtonInstance::~ImageButtonInstance(void)
 	image_dn = NULL;
 	delete listener;
 	listener = NULL;
+	selected = false;
 }
 
 bool ImageButtonInstance::mouseInButton(float mousex, float mousey, RenderDevice* rd)
@@ -93,7 +94,11 @@ void ImageButtonInstance::drawObj(RenderDevice* rd, Vector2 mousePos, bool mouse
 		positionRelative = Vector2(rd->getWidth() + position.x, position.y);
 	}
 	int renderimage = openGLID;
-	if(disabled)
+	if(selected == true && !image_dn.isNull())
+	{
+		renderimage = openGLID_dn;
+	}
+	else if(disabled)
 	{
 		if(!image_ds.isNull())
 			renderimage = openGLID_ds;