Updated the Path and Walk classes to use the new architecture. Refined many of the Abstract classes to use the new Architecture.

Refactored the graph package so generics are minimized with a focus on gneerifying the endpoints, major milestone in the design.

CHECKPOINT: Several fixes, but class implementation seems to be complete on the graph side. Time to start cleaning up the rest of the graph package.

CHECKPOINT: did some further cleanup of the generics and implemented some more methods int eh abstract classes.

CHECKPOINT: some more design cleanup including changing most contains() and remove() parameters to Objects in the generics, or the most general relevant type

CHECKPOINT: Minor clean up, removed comments, and implemented stubs in the implementation class for the simple graph.

CHECKPOINT: working interface structure for Graph extending Edge including Abstract implementations.

Fixed a bug in the Markov Random Field's joint probability function causing it to calculate incorrect results.