Created backend for game library.
 * Games that are saved are accessible via /library/username/gamename/
 * A user can access any of their games, but others can only get their public games
 * The newest version of the game is accessed (using the game's name)
 * Only playground games can be saved - not challenge games.

Outstanding:
 * Need to be able to enter a name and public/private value. Games are saved when compiled.
 * Need a library directory and for public games to appear on user pages.