Prepare for 2.8.8
Add log to destructible material list
Slight optimization to large construct batches

Filter out insane y values. This could be improved.
Refactor block and brush spells with abstract base classes.

Trying to apply some consistency, mainly.
Add a global auto-undo settings.

This involved a large refactor of the way the undo system is used.
Refactor undo queues, undo cancels pending batches
Fix really broken destructible material test.
Add "check_destructible" spell property to clearly indicate which construction spells use the destructible list.
Fix the replicate brush
Add /magic commit command
Add feedback to /magic commit command