Add getBlock and chat messages
Add getBlock and chat messages

Addition of 2 functionalities: "echo" and "echo <text>" allow for posting of messages on Minecraft screen, while still allowing non-MC messages to be used within Scratch; "getBlock" retrieves block data from Minecraft. Sensor values are called "BlockType" and "BlockDataType" to avoid naming clashes with BlockData and BlockTypeID variables.

scratch2mcpi/scratch2mcpi,scratch2mcpi/scratch2mcpi,scratch2mcpi/scratch2mcpi