Prior to this commit, when creating databases with a name or owner that has
characters which must be quoted (e.g., "pe-postgres"), the postgresql::server::database define
fails due to a SQL syntax error.
On psql 8.1, `pg_catalog.shobj_description` does not exist. Also, if the
database to comment is not the current db then this warning will be
raised and the comment will not be applied: `WARNING: database comments
may only be applied to the current database`
This fix uses the pg_* databases to find the comment based on the
database oid rather than the shared object description function.
