Add a talloc context as the first argument to each command in
notmuch.c.
-Write a "notmuch show" that displays a single thread.
+Make "notmuch setup" not index all messages, but only what it can do
+in a reasonable amount of time, (then add "notmuch index" so the user
+can complete the job when convenient).
Fix to use the *last* Message-ID header if multiple such headers are
encountered, (I noticed this is one thing that kept me from seeing the
same message-ID values as sup).
+Add support for the user to specify custom headers to be indexed.
+
+Add support for automatic tagging of new messages based on particular
+search criteria, (likely using an InMemory database for the new
+messages).
+
+Fix notmuch.c to call add_timestamp/get_timestampt with path names
+relative to the database path. (Otherwise, moving the database to a
+new directory will result in notmuch creating new timestamp documents
+and leaving stale ones behind.)
+
+Fix notmuch.c to use a DIR prefix for directory timestamps, (the idea
+being that it can then add other non-directory timestamps such as for
+noting how far back in the past mail has been indexed, and whether it
+needs to re-tag messages based on a theoretical "auto-tags"
+configuration file).
+
Audit everything for dealing with out-of-memory (and drop xutil.c).
Write a test suite.