"CREATE/DROP/ALTER SERVER should require privileges"
  Add check for SUPER privilege when executing CREATE/DROP/ALTER SERVER.
  Previously, any user even with only USAGE priv can execute those commands.


mysql-test/r/federated_server.result:
  Bug25671 - CREATE/DROP/ALTER SERVER should require privileges
mysql-test/t/federated_server.test:
  Bug25671 - CREATE/DROP/ALTER SERVER should require privileges
sql/sql_parse.cc:
  Bug25671 - CREATE/DROP/ALTER SERVER should require privileges
    Add check for SUPER privilege when executing CREATE/DROP/ALTER SERVER