Patch 1
 =======
 This patch performs a small refactoring of the mtr replication framework
 in order to enable multi-source replication in the framework.

 In this patch, we change the internal represenation of the topology:

- Before this patch, we used $rpl_master_list to represent the topology.
  It had the format:

  <number>{N}

  where the i'th <number> is the master of server i, or space if
  server i does not have a master.

  <number> is padded with spaces to $rpl_server_count_length
  characters, to ease string manipulation.

- After this patch, we use $rpl_connection_list to represent the
  topology. This variable has the format:

  (m<NUMBER>s<NUMBER>)*

  where each element represents a single master-slave connection;
  m<NUMBER> is the master and s<NUMBER> is the slave.

  <NUMBER> is right-padded with spaces to $rpl_server_count_length
  characters, to ease string manipulation.

  - change the following files:
      - rpl_change_topology.inc
        - generate rpl_connection_list correctly
        - use rpl_connection_list to iterate over slaves
      - rpl_for_each_slave.inc (rename to rpl_for_each_connection)
        - iterate over rpl_connection_list instead of rpl_master_list
      - rpl_generate_sync_chain.inc
        - change logic for computing the master of a given server so
          that it uses $rpl_connection_list instead of $rpl_master_list
      - rpl_init.inc
      - rpl_reset.inc
        - use rpl_for_each_connection / rpl_for_each_server
          instead of parsing rpl_master_list

  Patch done by sven.sandberg@oracle.com