I18N: trying to make sure that everytime the role pretty names are displayed they are localized (they may be message keys in the database). Since I couldn't figure out how to use the group type / relationship admin UI I didn't test this change as thoroughly as I would have like to...sorry
Added 'on delete cascade' constraint to bt_projects_apm_packages_fk, and sourcing bug-tracker-notifications-init.sql, so notifications actually work when you install bug-tracker :)