Leave point in body of message replies

gnorb-org.el: gnorb-org-setup-message

If we already have a To, or this is a reply, don't leave point in the To
header.
`gnorb-org-popup-agenda-popup-bbdb' keybinding

README.org: Practically everything else is taken
Think about merging mail commands

README.org: `gnorb-org-handle-mail' and `gnorb-org-email-subtree' do
nearly the same thing.
Limit to TODOs only in BBDB tag searches

gnorb-bbdb.el: gnorb-bbdb-tag-agenda

Used to show all tagged headings by default, only TODOs
with a prefix argument. This reverses those defaults.