Fix i-search to open up invisible citations as necessary.
+Emacs saved-search interface
+----------------------------
+Here's a proposal Carl wrote (id:87einafy4u.fsf@yoom.home.cworth.org):
+
+ So what I'm imagining for the default notmuch view is something like
+ this:
+
+ Welcome to notmuch.
+
+ Notmuch search: _________________________________________
+
+ Saved searches:
+
+ 55,342 All messages
+ 22 Inbox
+
+ Recent searches:
+
+ 1 from:"someone special" and tag:unread
+ 34 tag:notmuch and tag:todo
+
+ Click (or press Enter) on any search to see the results.
+ Right-click (or press Space) on any recent search to save it.
+
+ So the "saved searches" portion of the view is basically just what
+ notmuch-folder displays now. Above that there's an obvious place to
+ start a new search, (in a slightly more "web-browser-like" way than the
+ typical mini-buffer approach).
+
+ All recent searches appear in the list at the bottom automatically, and
+ there's the documented mechanism for saving a search, (giving it a name
+ and having it appear above).
+
Portability
-----------
Fix configure script to test each compiler warning we want to use.