Every agent perform cohesion towards tail points, instead towards other agents.
Useful for stuff like fibrous system, stigmergy , path finding etc..
Optimized Tail point search thanks to toxi PointOctree.
In the sketch : 2 attractors and 1 repeller ( mouse location )
Some example created with this code : http://vimeo.com/45254456.
W : apply wander
N : stop looping
F : Hide / display future location