new isValidDogId() function, removeDog() completed, Tree and Hash changed to work with pointers
Revert "new isValidDogId() function, removeDog() completed, Tree and Hash changed to work with pointers"

This reverts commit 1174fce297355dce1793d8ecc0774b343589cf96.
Revert "Revert "new isValidDogId() function, removeDog() completed, Tree and Hash changed to work with pointers""

This reverts commit 83a7952f2a21e82170927a34965759cde9d40933.
Updated displayDogInfoByIdSearch to work with new pointer style Hash Table