Gameplay additions, lighting, AI players, and lots more

- added tons of new recipes, blocks, and tiles
- added player scores (with a sorting leaderboard)
- separated player class into AI and Human
- AI players build castles (will attack soon)
- fixed inventory bug where blocks and tiles could not be dropped
- added control clicking to drop entire item stacks
- added tile-based lighting (disabled, still a work in progress)
- added a day/night cycle
- items are shown being held by players and NPCs
- improved entity collision and made them collide with each other
- spawners can now properly spawn entities with an inherited owner (ex Bob's spawner will spawn an NPC that has Bob as an owner)
- spawners also have a new tag "requires_food" which will spawn things only if the owner is not going hungry (entities spawned reduce overall food score)
- dig up the grass; there's a chance you might find ores
- players can now break stone tiles