Attached is a small patch for adding "edit-and-execute-command" readline support to psql. Bash has this concept and I miss it when using psql. It allows you to amend the current line in an editor by pressing "v" (when in vi mode) or "C-x C-e" (when in emacs mode). Those are the default bindings from bash although of course they can be amended in inputrc.
The only difference from \e is that you don't need to jump to the end of input first, I guess?
