Release notes pgsql_tweaks v0.3.0

This release faces several major changes for the project itself. The main repository has been changed from GitHub to GitLab. The sources on GitHub are only a mirror from now on.

The following changes have been done:

• A bug with the view pg_functions with PostgreSQL 11 has been solved, see #1 for details.
• The function sha256 is now installed, if the extension pgcrypto is found during the installation of pgsql_tweaks.
• The function array_trim has been added, it offers a solution to remove duplicates and/or empty entries from arrays.
• The view pg_table_matview_infos has been added, the view contains detailed information about tables and materialized views.