+Fix notmuch_query_count_messages to share code with
+notmuch_query_search_messages rather than duplicating code. (And
+consider renaming it as well.)
+
+Provide a mechanism for doing automatic address completion based on
+notmuch searches. Here was one proposal made in IRC:
+
+ <cworth> I guess all it would really have to be would be a way
+ to configure a series of searches to try in turn,
+ (presenting ambiguities at a given single level, and
+ advancing to the next level only if one level
+ returned no matches).
+ <cworth> So then I might have a series that looks like this:
+ <cworth> notmuch search --output=address_from tag:address_book_alias
+ <cworth> notmuch search --output=address_to tag:sent
+ <cworth> notmuch search --output=address_from
+ <cworth> I think I might like that quite a bit.
+ <cworth> And then we have a story for an address book for
+ non-emacs users.
+
+Provide a ~me Xapian synonym for all of the user's configured email
+addresses.
+
+Database changes
+----------------
+Store a reference term for every message-id that appears in
+References. We just started doing this for newly-added documents, but
+at the next convenient database-schema upgrade, we should go back and
+fix old messages to be consistent.
+
+Start indexing the List-Id header, (and re-index this header for
+existing messages at the next database upgrade).
+
+Start indexing the message file's directory ana make it available for
+search as "folder:" (and re-index this value for existing messages at
+the next database upgrade).
+
+Add support for the user to specify custom headers to be indexed (and
+re-index these for existing messages at the next database upgrade).
+
+Test suite
+----------
+Start testing --format=json.