The postgresql_user module has several drawbacks:
* No granularity for privileges
* PostgreSQL semantics force working on one
  database at time, at least for Tables. Which
  means that a single call can't remove all the 
  privileges for a user, and a user can't be
  removed until all the privileges are removed, 
  forcing a module failure with no way to 
  work around the issue.

Changes:
* Added the ability to specify granular privileges
  for database and tables within the database
* Report if user was removed, and add an option to 
  disable failing if user is not removed.