[engine] Unit-specific undo

[irrevenant]

At times it would be really nice to be able to select a unit and undo their move specifically.

I don't know if this would be better as a replacement for the current undo, or as an alternative to it (Ctrl-U?). Certainly it's only worth doing if it can be implemented in a clean, unconfusing way.

I can't be the only person to move out my army, then realise I moved the first one to the wrong place.

P.S. The "[]" tags are new since I was last here, I hope I used them correctly. Where are they documented, please?

[Gambit]

Have you tried the whiteboard in 1.9? It's not exactly this, but similar.

[irrevenant]

Have you tried the whiteboard in 1.9? It's not exactly this, but similar.

Is that "Planning mode"? I just noticed it but haven't tried it yet.

It looks good, but it'd be best if you didn't need to know in advance that you'll want to undo.

Aside: Gmail just implemented an undo for discarded messages. It's beautiful. No nagging "Are you sure you want to...?" messages or special mode you need to activate. Just an "Oops, I didn't mean to!" option there for if you need it.