Pathfinding API and Demo v0.41 released

The distribution of the pathfinding library has changed slightly. The API release will now only contain the code and docs. Removing the demo data from the API release saves significant download time on slow connections.

New changes in 0.41:
1) A custom hash table, optimized for speed, is used to store bin data rather than using large, multi-dimensional arrays. See the benchmark tests versus std::map and stdext::hash_map in the Utils project. Here's a graph: http://openskynet.sourceforge.net/img/HashBenchmarkTests.jpg
and some stats: http://openskynet.sourceforge.net/HashBenchmarkTests.csv

Of course, it's not as fast as the previous arrays, which were large enough to store all bin keys, but the memory gains should be worth it. \todo Benchmark the memory usage compared to 0.40.

2) The global grid's axis divisions are now resizable.

3) The testing framework CPPUnit is now being used.