[Dev] Blocking UI in 0.7

[Andi Vajda]

> I was hoping, someday, to have the commit point be the unit of undo, e.g. if 
> you did a delete, you'd commit after the operation. Of course this requires 
> the ability to roll back changes to previous commit points, which doesn't yet 
> exist.

Regardless of how realistic tying transactions to undo boundaries is, it is 
possible to travel a view up and down the version list. What is not yet 
possible is the discarding of changes after a given version to effectively 
roll them back.

Andi..