- Added initdb_user configuration, renamed postgres_user and postgres_group to user and group

- Corrected inadvertent changes to postgres_user
- Fixed postgres_user
- Explicitly list the grain that we're filtering by even though it's
  default
- Place *BSD user and runas into osmap instead of hardcoding

postgres/defaults.yaml

@@ -20,5 +20,6 @@ postgres:
   pg_hba.conf: salt://postgres/pg_hba.conf
   commands:
     initdb: service postgresql initdb
-  postgres_user: postgres
-  postgres_group: postgres
+  initdb_user: root
+  user: postgres
+  group: postgres