move(), turn_left(), pick_beeper() y put_beeper()
are the four basic activities that Karel can perform. If you turn on Karel's
superpowers with load_super_karel(), then she can also
turn_right() y turn_around().
move() turn_left() put_beeper() pick_beeper() turn_right() turn_around()
Value
These functions don't return anything, but make changes in Karel's
world that are visible when all the actions are run through
run_actions().
