Pathfinding API and Demo v0.35 released

New major features in version 0.35:

1) Piecemeal pathfinding - multi-threading support was removed in version 0.3 due to lack of time to fully debug it. However, incremental pathdfinding provides many of the benefits of multi-threading without all the pain. It is a user-settable option to determine the number of seconds alloted for pathfinding each call.

2) Batch pathfinding calls - Multiple drivers are often pathfinding w/ the same subdivision of the grid at any given time. Huge performance savings can be had in both speed and memory by sharing occupied bin data.