Maintaining user roles and permissions in Postgres - general question

Does anyone have a recommendation for maintaining user permissions on
a changing database?  The lack of an option to grant specific rights
to all objects of a given type within a Postgres db obviously places
the burden on the administrator to keep roles updated as objects are
added and dropped from a given database.

Unfortunately for us, we don't have a dedicated db admin, so this task
falls into the hands of developers who are probably less adapt at this
kind of task ;)

Is there a utility or set of scripts out there that helps a db owner
with permissions admin?

Thanks