The number representation in the implementation has been changed, leading to a significant speed up. A new algorithm handles the calculation of all-pairwise distances on a set of trees, making all-pairwise calculations much faster on sets of similar trees. The distance calculated is the non-oriented distance (which is just half the distance previous versions calculated).
An alternative algorithm has been added to the tool. This new algorithm is significantly simpler than the old one, and while it does not guarantee a O(nlog^2n) runtime performance (but a O(n^2)) it works significantly faster in practice on smaller trees.
The tool has been updated to perform all-pairs distance calculations
rather than only the distance between a single pair of trees. It uses a
DAG build from the input set of trees to avoid redundant work, and thus
performs better on a set of trees than the previous version would if
called on all pairs of trees.
