ChunkLoader Upgrade now loads a 3x3 chunk area centered on the robot.
Made the loaded chunks a set, because I don't trust it to not be dynamically re-generated each time it's accessed by `contains`.
Merge branch 'master' of github.com:MightyPirates/OpenComputers into master-MC1.7.10

Conflicts:
	src/main/scala/li/cil/oc/common/event/ChunkloaderUpgradeHandler.scala