Save / load support

Just finished adding a basic save game implementation.  It saves the current level and all your constructions, but there are currently a few limitations:-

• Fixed number of available save slots.
• In multi-player, can only save or load a game on the server machine (clients don’t have all the necessary data locally available).
• Does not save your player’s position, you’ll spawn randomly (like when starting a new game).

Try it out at the link above!