[MariaDB Packagers] MariaDB Galera Cluster 5.5.57 release prep

Prep work for the MariaDB Galera Cluster 5.5.57 release has begun. Expected release date is Wed, 26 July 2017. Draft release notes and changelog: - https://mariadb.com/kb/en/mariadb-galera-cluster-5557-release-notes/ - https://mariadb.com/kb/en/mariadb-galera-cluster-5557-changelog/ As usual, the release notes and changelog are still in draft form at this time and they may be updated prior to release. Thanks. -- Daniel Bartholomew, MariaDB Release Manager MariaDB | http://mariadb.com