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.
The convention here is to have the CreateActor on the same line as the FrameEndTask, and then have the inner braces at the same indentation (like an `if` or `for` block).