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.
Good point. But in this situation if after N ticks the worm looks for a new target the only one in range would probably still be the trike that was baiting it.
Maybe we could work around this by making the worm disappear after N ticks of chasing? And then a new one will spawn somewhere. (The worms in the book do get tired, so it could work)