Add mariadb_clustercheck image with xinetd and clustercheck binary for haproxy
checking of galera status.
Reorganise existing mariadb images by creating mariadb-base and mariadb-server.
Existing mariadb image will be deprecated (in a separate change).
Change-Id: Ib601f64e1514521154beeaac40f0c058a7119408
59616d4423