This constructor instanciates a Player with
the name "unnamed DefaultPlayer", no game tree search option,
tracking disabled and no game level overwrite.
instanciates a player with the given playerName, searchOption and
tracking; game level overwrite is set to 0; for searchOption values
see #setSearchOption().
MoveEvaluater is used by the method selectMove() from the enclosing
TemplatePLayer class in case of a time-limited search to allow each
move to be examined efficiently in a separate thread.