Fixed BinTreeTest errors and added Handle to interface

BinTreeTest has no red errors. Still has to be correctly implemented
(along with BinTree) to handle creating new objects with the
MemoryManager
The interface HasCoordinate was replaced with HasCoordinateAndHandle so
that the Watcher has a Handle and can be accessed by BinTree
Watcher was updated to support new interface
WatcherTest was updated to support new Watcher