title: How to change node icon in veins
body: <p>i am trying to simulate some of congestion avoidance techniques in omnet++, one of those techniques are basing on special vehicles called <em>super vehicles</em>, so i have to make those nodes (vehicles) during simulation with a different icons , the default in veins are car icon, i search a lot on which class that could has this options , but i could only find some parameters in <code>BaseMobility.cc</code>, so my question is how to change the nodes icons in veins ? , and if is it possible to change the icon of only specific nodes</p>