This is a step towards making replication a library, such that the 5.6 rpl- lib can be plugged into the 5.5 core [WL#5675]. In this worklog, we move various functions that are defined in the wrong place, to the right place. - Move append_query_string away from log_event.cc, into core. - In sql_parse.cc, it creates an Incident_log_event. This is for debugging only and is used by two tests (rpl_incident.test and binlog_incident.test). This can be moved into rpl-lib. - net_request_file in rpl_slave.cc is used by sql_load.cc. It's not clear if this functionality is obsolete in rpl-lib or not. It should probably be moved to core, and either we remove it from rpl_slave.cc or we make core expose it so that rpl_slave.cc can use it. - In sql_load.cc we reference active_mi->rli->slave_patternload_file. This is only needed for an assertion. The assertion can just be removed.