added enum class for holding Actor Types
added class for creating random things
added enum class for holding all legal directions
added class for being the father of the first actors
added class for holding statistics about the world
actor now has method for getting the type of the actor
tile now has method for determining whether or not the tile has an actor of a given class
world now holds an instance of the statistics class and activates it when a step is performed
corrected custompanel so it now gives grass to arguments in constructor
updated grass, so it now may spread and have children