Support of arbitrary 3D tiles

[jarod46]

I would like the support of arbitrary 3D Tiles, (https://groups.google.com/forum/#!searchin/recastnavigation/layer|sort:relevance/recastnavigation/L5rBamxcOBk/5xGLj6YP25kJ) to add the possibility to do not have to generate/load the entire meshes in vertical axis, thanks (and thanks for your help Ben).

[grahamboree]

While the problem outlined here is fairly clear, the solution is not so I've added the "needs more info" label