When this function was originally written, the 'message' object was
always destroyed locally, so I thought it would be good to use a NULL
talloc context to make it more obvious if there was any leak.
Since then, however, this function has been changed to optionally
return the added message, and in that case we *don't* free the message
locally, so let's let the database be the talloc context.
We never did export any interface to get at these, and when I went to
use these, I found them inadequate, (because I wanted to distinguish
address found in from: from those found in To:). Meanwhile, it was
easy enough to extract addresses with a search like:
notmuch show tag:sent | grep ^To:
so the storage of contact terms was just wasting space. Stop that.
This will allow for things like the database path to be specified
without any cheesy NOTMUCH_BASE environment variable. It also will
allow "notmuch reply" to recognize the user's email address when
constructing a reply in order to do the right thing, (that is, to use
the user's address to which mail was sent as From:, and not to reply
to the user's own addresses).
With this change, the "notmuch setup" command is now strictly for
changing the configuration of notmuch. It no longer creates the
database, but instead instructs the user to call "notmuch new" to do
that.
