databases/mariadb101-server: Update to 10.1.16

• Update to latest version 10.1.16
• Switch from USE_OPENSSL to USES= ssl
• Switch from USE_MYSQL to USES= mysql
• Switch from WANT_MYSQL_VER to USES= mysql:101m
• Fix liblz4 linking for mroonga
• Register MROONGA lz4 depends
• Register libxml2 depends