1.5 taxonomy

Addresses issues raised in:

- http://croogo.lighthouseapp.com/projects/32818/tickets/484-taxonomyterms-admin_delete-not-deleting-term#ticket-484-4
- http://croogo.lighthouseapp.com/projects/32818/tickets/484-taxonomyterms-admin_delete-not-deleting-term#ticket-484-6