Challenge #165 [Hard] Simulated Ecology - The Forest

- TODO: Output is graphical only. Need to print out the list of events
  for each month and year.

  Known bug that gets the program stuck in a loop when a new entity
  tries to find a random location for entering the forest when there
  are no empty spaces.

  Bears get stuck when they are completely surrounded by trees. They
  should be able to move through tree spaces.