add option to [E]dit shell commands

[cori]

I'd love to see an additional option in the shell command output for Edit, so if you get a close-enough-but-not-perfect result you can update it (or e.g. modify it for another set of options) on the command line before execution. I currently do this by copy-pasting, but that takes my hands off the keys.

The options might end up being

[E]dit, E[x]ecute, [D]escribe, [A]bort or something.

[cori]

This is perhaps a duplicate of #132, which didn't get a lot of uptake on the discussion forum. Perhaps better tp cpntinue this there.