Added class and methods to observe actions as they are executed.
Currently a live action viewer is provided. This is useful for watching
the events of a learning algorithm or Monte-carlo-like planning
algorithm in action.
added tabular policy iteration to stochastic planners
added mountain car domain
updated readme
adding canvas padding to mountain visualizer for better viewing
by default set the value iteration state reachability to not prune
states from terminal states so that it capture more of the state space.
Also added a method so that this behavior can be toggled to enable
pruning.
added hashCode method to GroundedAction.