Implement nearest point query for AI Input obstacle avoidance

[robwalch]

See http://dl.dropbox.com/u/2494815/demo/index.html (Query Tab)

map collision notes (i think current solution is pretty good)

• How to prevent default collision behavior then based on z location? Layers, groups or type callbacks?
• Currently we use type callbacks with expensive results, and storing. Maybe this an layers offers a better solution?

[robwalch]

How will AI use this?

1. New map features:
   • way points
   • a-star navigation grids (difficult to create and maintain as props and obstacles move)
   • pathfinding using above or other techniques?