v0.5

• Add blocks with light levels: glowstone, torches, etc. (GH-21)
• Add signs, displaying wall/standing and writing on in web client with "`" (GH-20)
• Add option to change or disable the Bukkit entity used to represent web users (GH-16)
• Add option to change the Bukkit world where the sandbox resides: mc.world (GH-4)
• Add options to limit web user interaction with the world: disable break/place blocks, writing on signs, chatting, seeing other player chat, and seeing other players (GH-17)