Add utility for optimizing and retopologizing geometry

[gkjohnson]

When performing CSG it's best to have a minimal amount of triangles to intersect. With CSG operations some planar surfaces may have complex triangulations with internal vertices. The utility should use the half edge map to determine coplanar triangle connectedness, derive outside the outside loop, and retopologize using the three.js Earcut functionality.

[gkjohnson]

Closing in favor of #96