go fmt
Set the InReplyTo field when sending a draft from the GUI.
Added reply quoting to the GUI.

Ideally this should quote only the selected text if any text is selected
in the message viewer when the user presses reply.  At least that's how
my email client works.

I assume Go initalizes the two local varialbes I eliminated to zero,
but I thought it looked cleaner to initalize them explicitly and
and set them if inReplyTo is set.  <shrug>