Breaking a disk drive was not stopping the record being played as the
block event never reached the client. Instead, we send a custom packet
which starts/stops music at a given location.
We also remove all the plumbing for eventReceived/sendBlockEvent from
the generic block/tile classes, as they are no longer used.
Closes#443
Updated the source code to the version shipped as the 1.80pr0 alpha
release. Also removed some unnecessary files from the LuaJ subfolder
which were bulking up the repository.