[PATCH 1/3] emacs: use a single history for all searches

[Dmitry Kurochkin]

I got some positive feedback for replacing notmuch-hello search input
with a button wich would call `notmuch-search' and read input from
minibuffer as usual.  This way we do not have to maintain 2 search
interfaces and get history, tab completions and other minibuffer
features in notmuch-hello search without having to reinvent the wheel.

So I plan to go with this approach and this patch series is obsolete.

Regards,
  Dmitry