Moving logic for finding sibling block for double-lengths to elixr
Adding config for which entities should never be rolled back (default creeper). bug 452:resolved. Adding config for which blocks should never be rolled back (tnt, fire, lava) bug 306:resolved
Added tracking for discs popping out of Jukeboxes on block break
Now tracking users removing/inserting new discs into jukeboxes. bug 563:resolved