MordorQuest: implementing the changes made in the specification: briefly now the animator can apply the fog() mechanism, the towers are in a type specific and thread-safe list (copyonwritearraylist) which optimizes access and modification, due to the fact that the insertion of elements is way too rare compared to the reading of elements in the list of towers.

after that the towers are capable of having and managing the FogStatus (newly created), and selecting new targets according to its effects and existence.

TODO: refin and FIX the PoisonStatus and SlowStatus, EnemyTroop.split()

and random in PathFinder.