Remove Runnable from Task

Running a Task is something that should be left to the scheduler, not plugin code.
Added a class containing an instance of all block types.
Added the blocks also to ItemTypes, Items coming soon once wrist recovers
Added all items thanks to phroa
Removed block versions of items that have alternate held items
Sync ItemTypes list with what is actually registered as an item
Ensure the BlockTypes list is syncronized too
Merge branch 'blockevents', remote-tracking branch 'upstream/master' into blockevents
Rewrite block cause system to be more extensible