* include/galera_cluster.inc : Configures galera cluster with 2 nodes.
* include/galera_init.inc : Opens named connection with all the nodes.
* include/galera_end.inc : Closes all the connections.
* include/galera_connect.inc : Opens a named connection with a single
  node.
* include/galera_diff.inc : Runs a specified SQL query on all the nodes
  and diffs the output.