Fix problems when BBDB is not present and gnorb-bbdb is not loaded.

I'm experimenting with gnorb but have BBDB 2 installed, and therefore don't want to try gnorb's BBDB integration.  I don't load gnorb-bbdb, but still have to make the following changes to run gnorb without errors.

I hope that you find the patch useful.
gnorb-bbdb must be required before gnorb-org so that the BBDB functionality will be hooked in properly (see my other answer).