Modifications to binary heap to bring A* pathing closer to client:
* Break equal f value ties in same way
Modifications to binary heap to bring A* pathing closer to client:
* Don't break out early from BHEAP_POPINDEX
Modifications to binary heap to bring A* pathing closer to client:
* Implement a BHEAP_UPDATE function which apparently matches the behaviour
  of the bheap used by the client A* impl.
  The previous POPINDEX+PUSH approach results in pushing the last
  heap element, this doesn't.