Obe's Infested blocks

First release.

• Mining a block turns the six blocks touching it into the block you mined. It never spreads through the air.
• Only survival and adventure players spread blocks.
• Containers, spawners, signs, bedrock, portals and door, bed and tall-plant halves are never converted.
• Blocks that need support (torches, plants, rails, doors…) don't spread.
• Spread leaves don't decay.