Added a couple of new utility functions for example for calculating distances between geometric objects (points, line segments and triangles) and a bit of clean up.
Minor improvement in topological edge and face removal.
Performs laplacian smoothing when the result is better than MIN_QUALITY (in addition to when it improves the quality).
Velocity function is no longer abstract. It calls the deform function without setting the destinations of the interface nodes. Consequently, the mesh is optimized without interface changes.