Update pick's archive message to respect notmuch-archive-tags. Also
split archive message into an archiving part and a separate
"then-next" part, to move more inline with show. Update the keybinding
so default behaviour is unchanged.
Previously if you carried on past the last message in a pick view pick
would get confused and `forget' about the split pane and would try and
re-split when moving up again. This was due to faulty logic in
notmuch-pick-show-message: something that should have been in the (when message)
clause was not.
Thanks to jrollins for the bug report.
If the user pressed return on the end result status line it gave a
blank message. Modify the function notmuch-pick-get-message-id to
return nil rather than an empty message-id in this case to fix this.
This also fixes a bug in the (lack of) quoting of the id string.
