New Update - Stealth ASCII

New changes for the game:

1. The level exit is now a door (+) which needs to open with a key found on the each map
   
2. When pressing a movement key down, player keeps moving  until hits an obstacle or picks up something
3. The guards have now a proper AI allowing them to react player's actions, like picking up items too close
4. The guards can now wake up their adjacent knocked-out colleagues
5. Items no longer stop guards from moving, instead guards will just switch places with them
6. Other minor fixes