Changed from ChunkPosition to new Position class
* ChunkPosition is immutable and I plan to reuse these objects as much as possible
* Requesting tube now allows imported items if the filter is empty

TODO:
* State information about the path must be stored during routing:
  - Need to keep track of colours so that impossible routes will not be chosen
  - Need to set appropriate direction when checking if an item can enter
Made the routers update the tube items direction before testing against it
* Would still like to update colours, but this requires some simulate method to show what would have happened if that item passed through this tube
* Fixed bug with requesting tube where logic would execute on the client side
* Fixed bug with requesting tube where they could be pathed through