Implementations for player and enemies

-Modified the to-do list
-Added one more enemy and changed the positions of other enemies.
-Added list of commands to be used as a look up table.
-Replaced the way objects were being updated. Modify() gets called now instead of update, this way we can take input from the ANN.
-Enemies move the frogger way now.
-Implemented notify function for player (should take input from ANN).
-Implemented update function to take action when there is an input from the ANN.