Release 2.4.0

Summary
-------
This updates adds the ability to change permissions on tables, create
template databases from normal databases, manage PL-Perl's postgres
package, and disable the management of `pg_hba.conf`.

Features
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- Add `postgresql::table_grant` defined resource
- Add `postgresql::plperl` class
- Add `manage_pg_hba_conf` parameter to the `postgresql::config` class
- Add `istemplate` parameter to the `postgresql::database` define

Bugfixes
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- Update `postgresql::role` class to be able to update roles when
  modified instead of only on creation.
- Update tests
- Fix documentation of `postgresql::database_grant`
Merge pull request #213 from hunner/release_2.4.0

Release 2.4.0