D2k: Sandworms implementation

Using Mailaender's code as basis, this is my implementation of the sandworm behavior. It is still WIP, but you can get an idea of how it looks from the shellmap.
If you live underground (and move horizontally) and you jump a few hundred meters in the air (vertically) you would need a couple of seconds before you get back in a position to move (horizontally)  ;)