Is there a way to add org-habit to the
org-modules list without using org-custom and without
specifying all the modules at once, like this:

(setq org-modules (quote (org-bbdb org-bibtex blah blah blah)))

I'm looking for something like this:
;; Except this doesn't work :-)
(append org-modules (list ('org-habit)))

Thanks,
--Nate