Added Stack and Queues
Some more puzzels
Added compress String puzzle.
Added BinaryTree stuff
Added HeapSort.
Added Insertion Sort.
Added Quicksort
Restructuring into packages.
Renamed DataStruts to LinkedListOperations
Added code and test for removing duplicated from linked list.
Modified code and test for checking if linked list contents are palindrome.
Increasing some code coverage.
Added set of stacks.
Added Generics to Set of Stacks
Added Animal Shelter puzzel.
Added package for data struts operations.
Added GraphNode and Graph operations.
Added an assertion in BinaryTreeOperations Test
Added getInorderSuccessor to Binary Tree operations
Added Get first common ancestor for a Binary Tree and its test.
Added subtree function to BinaryTree.