* begin allowing "post processing" of chunks
- restores legacy capability to continue saving edits in the background after sending the chunks
- speeds up the edit clientside
- nail in the coffin of the terrible and staticly coded coreedit
- We should totally make IronGolem work so Core* is no longer used by anyone
* begin allowing background history saving
* Handle post processors in queues properly
* Use futures for postprocessing so we're not waiting for them needlessly
* better use of closed boolean
* Reword