mutt: Add "O" macro to save original message
mutt: Add "O" macro to save original message

Because I can't remember the trick mentioned in 78e9ef2ff714b.

wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent