Move text up and down in the editor

[vkbo]

One feature of code editors that I'd like to have is a keyboard shortcut to move text up and down in the document. Either the line I'm working on, or a selection. This should be available with keyboard shortcuts Alt+Up and Alt+Down.

Since this is potentially a disruptive feature, as users may do this accidentally, it should be optional. It could be grouped in Preferences together with the auto-select word feature.