better reproduction for the example
refactor and simplify randomness interface
added symbolic regression example
sexual reproduction of tree structures
abstracted some symbolic regression stuff to generic treenode stuff
added langfords ant example
fix some bugs in the ant example
factories...factories everywhere...
trying to simplify some of the generics madness
removing some dead code
simplifying, simplifying
cleaning up the WeightedPopulation class by using a priority queue
switching back to an arraylist + sort
added some tests, fixed some bugs
need to clone trees before merging them