Undo for terrain manual editing

[demostenes]

It would be very useful to have undo for terrain brushes. It would also mitigate various random issues with these tools. For example sometimes you use smooth tool and it creates spike in height map to the heaven. No undo, so cancel and everything again. Quite frustrating. 

Currently there is lots of issues with these terrain tools, but it is so random and occasional, that there is no chance to make some reproducing steps. I am not sure if it makes sense to report it, so at least such mitigation would be fine.

[morbid]

Demostenes, 

indeed, there's a bunch of problems with current terrain brushes realization. We keep working on terrain tools and Undo\Redo was already planned. I'll ping our tools team with this.

[demostenes]

Ok, thanks.