Pathfinding and provisional combat

Got path finding working! Turns out it is extremely important to keep a closed set of nodes you have already visited so you never check them again. If you don't rule these out some path finding queries that require paths that are significantly higher than your initial heuristic estimates will have you going back and fanning back out over points you have visited (until those paths bloat up and become more expensive). Amit's AI pages seem like they will be pretty useful for tweaking it but for now it works good enough.

I have now that path finding has been working I have started work on basic combat which mostly involves shooting a space dragon with a test weapon. I have also spent some time writing more tests mostly around the UI system. Replacing nose as my test runner with pytest.

Also started thinking about random spaceship generation algorithms since my big KD tree divided dungeon box doesn't really set a very space like mood (unless you want a borg cube). Once I have combat working in a basic way I will be focusing on that and getting some kind of world map (universe map?) working.