Removed single methods for getting the size of the lists representing
robots and fences as well as the single methods for getting a specified
robots or fences object. Replaced them with methods to get a
unmodifiable list of robots and fences respectively.
Removed getter for robots/fences size and specified robots/fences
objects. Replaced them with getters for unmodifable lists of the
respective objects.
Applying changes in methods for getting the robots'/fences' amount and
single objects.
Updated date of contemporary version.
Applied method changes for getting amounts for robots/fences lists and
getting individual robots/fences objects.
Updated date of current version.
Applied changes for getting the amount of the robots list and individual
robots objects.
Applied changes in methods for getting the robots' list's size and an
individual robots object.
changed arena to normal gameboard.
Changing ArrayList<Tunnel> to HashMap<index, Tunnel> to avoid
variegating tunnel indices after removing one tunnel from the list.
Moved all methods concerning tunnel rendering to extra class TunnelRenderer.
Created new class TunnelRenderer responsible for all drawing jobs concerning teleport tunnels. Also implemented changed type of "tunnels",...

...is now HashMap and uses Iterators for running through the tunnel map.
Fixed NullpointerException in checkTeleport() (once again...).