Place point somewhere useful after setting up message

gnorb-org.el: In `gnorb-org-email-subtree' and `gnorb-org-handle-mail'
What on earth was that still doing there?
Allow attaching in all captures.

gnorb-gnus.el: New option gnorb-gnus-capture-always-attach

When set to t, behave as if all capture templates had the
:gnus-attachments key set to t.
Refactor gnorb-org mail-related stuff.

gnorb-org.el: `gnorb-org-email-subtree' and `gnorb-org-handle-mail' make
more extensive use of the underlying `gnorb-org-setup-message'.
First go at `gnorb-org-agenda-popup-bbdb'

gnorb-org.el: New function for popping up a BBDB buffer of BBDB records
corresponding to the tags search underway. Also new options:

gnorb-org-agenda-popup-bbdb
gnorb-org-bbdb-popup-layout
Change README.org wording

To reflect the refactoring of the gnorb-org mail stuff
Move mail search backend stuff to gnorb-gnus

Specifically, we've deleted these two options out of gnorb-bbdb:

gnorb-bbdb-mail-search-backends
gnorb-bbdb-mail-search-backend

And added these two options to gnorb-gnus:

gnorb-gnus-mail-search-backends
gnorb-gnus-mail-search-backend

And changed `gnorb-bbdb-mail-search' to use the new options.
Documentation and whitespace changes