Check maxNodeTris after split

[gkjohnson]

The geometry in the benchmark with the default options winds up having the following min and max triangle counts:

tris: { min: 1, max: 76 }

despite the maxNodeTris option being set to 10. This could be solved by checking to make sure that both children counts will be above the tris threshold before splitting the nodes into separate children.

[mqp]

Nice catch, that seems right.

[gkjohnson]

As discussed here I think this is just an artifact of a naive split strategy and not something that should be addressed.