Added iterative version of optimal tree generation.
Added a package structure.
Added dependency files.
Deleted orphaned OptimalPseudoTreeGenerator.java.
Fixed bug in cost function; pruned nodes now contribute 0 cost. This
appears to increase running time considerably, and reduce the cost of
the final tree considerably. Maybe there is still a bug?
Merge branch 'master' of git@github.com:acgs/OptPseudoTree.git