Don't add empty 'extra' fields to chat msg JSON
Merge pull request #218 from NSDex/master

Don't add empty 'extra' fields to chat msg JSON
moved size constant and cleaned the index math
added the missing server bound DisconnectPacket used in MinecraftClient.Disconnect
added check for division by zero
added null check to avoid exceptions
minebot forms demo
miner state machine
updated to latest minecraft
labyrinth