add assignment 4 starter code
reformat given files to stupid 2 space indentation
implement and test BinaryTree::height2
create stubs for isBalanced
fix height2 test code
test height2 with 10,000 random numbers
fix height2
implement BinaryTree::isBalanced
test BinaryTree::isBalanced
add stubs for order number methods
implement BinarySearchTree::getNode
implement and test BinarySearchTree::preOrderNumber
implement and test BinarySearchTree::in/pre/postOrderNumber