Change default game turn to zero
fix(Game.js, etc): Change hero properties to prevent circular references,
Fix turn handling when heroes die
Now working with many turns, 4 heroes
Integrate with remote mongo DB (if available), or local mongo DB (if local)
Modified diamond mine owners to never be undefined
Merge pull request #9 from gjtrowbridge/refactor-game-running

fix(Game.js, gameRunner.js, more): Update game to not exceed maximum call stack