Support an operation to compact the history without writing an archive about acid-state

[dmjio]

Per the docs,

createArchive: Move all log files that are no longer necessary for state restoration into the Archive folder in the state directory. This folder can then be backed up or thrown out as you see fit. Reverting to a state before the last checkpoint will not be possible if the Archive folder has been thrown out.

Might be beneficial to have a separate thread monitoring that directory. I don't think acid-state does this out of the box since it probably doesn't want to be responsible for data loss. Since deleting old archives assures you won't be able to rollback to an earlier version.