Swapped indexes in astar.h

[fwanderlingh]

Hey man, while using your fantastic rep I encountered a bug in the astar header, in particular the indexing of the grid in the neighbor search when using nx,ny and cx,cy where swapped. That was causing the algorithm to search blocks that could be occupied by walls if the map was different from the sample one. I'm using your astar header in one of my repositories, so if you want feel free to have a look at the changes I've done 😉

I'm not using the github tools to fork the rep and request a merge since I'm somehow new to git and I don't want to create a mess 👅

[xtaci]

yes ,it's true.
i'll try to fix this problem. if you get familiar with git , you can just simply "pull requests".
thanks guy!

[xtaci]

I've done some optimization to the astar algorithm, and also some comments.