TODO

- A better build setup (eg: cmake)

- Iteratively alternate between optimization and progressive feature matching

- Alternative feature matching strategies
    - Move neighbors when snapping vertex (ie: energy/spring model, 
        displacement kernel).
    - Snap lattice vertices to features before doing isosurface stuffing.
    - OR Snap lattice vertices to feature endpoints (not full features) 
        before doing isosurface stuffing.

- Ensure optimality of path search
    - Right now not guaranteed to be optimal because the tet inversion test
      depends on the path taken to a particular vertex, not just the edges
      and weights of the graph.

- Use tet quality metrics to choose optimal paths during edge snapping
    (instead of just minimizing the distance that vertices are moved).
    - This may require Bellman-Ford (for negative edge weights), because
        it's possible that snapping a vertex could actually improve the 
        tet that it's a part of (our distance-minimizing algorithm
        assumes that moving a vertex will always make the tet worse).

- Improve mesh data structure efficiency
    - ie: adjacency list for triangle mesh, O(1) neighbor lookup, improve 
        efficiency of graph search in match_features
          - Efficient TriMesh class created (half-edge data structures),
            but it isn't applicable to the mesh we've been using that 
            indexes into the vertices of a TetMesh.


Less important stuff:
- Better tet-mesh data structures
    - More efficient traversal of edges, triangles.

- Tet Quality measures
    - Design pattern for plugging in arbitrary quality measure?

- FeatureSet::consolidate()

- Allow topology changes when matching features.
    - If unable to find path between two vertices separated by two boundary
        triangles, do an "edge split" or "edge flip" on the edge separating 
        them.

- Curvature for automatic feature detection to detect feature points.

- Additional misc optimizations

- Handle more mesh file formats
    - .OFF (input, triangles)
    - .ELE (output, tets)