Fixed issues found by QA (Elena)

- Added parameter to reset_logs() so that one can specify if new logs should be created.

mysql-test/include/setup_fake_relay_log.inc:
  There is no orphan relay log files anymore
mysql-test/mysql-test-run.pl:
  Added multi_source to test suite
mysql-test/suite/multi_source/info_logs.result:
  New test
mysql-test/suite/multi_source/info_logs.test:
  New test
mysql-test/suite/multi_source/my.cnf:
  Added log-warnings to get more information to the log files
mysql-test/suite/multi_source/relaylog_events.result:
  Added cleanup
mysql-test/suite/multi_source/relaylog_events.test:
  Added cleanup
mysql-test/suite/multi_source/reset_slave.result:
  Updated results after improved RESET SLAVE
mysql-test/suite/multi_source/simple.result:
  Updated results after improved RESET SLAVE
mysql-test/suite/multi_source/simple.test:
  Syncronize positions before show full slave status
mysql-test/suite/rpl/r/rpl_row_show_relaylog_events.result:
  Updated results after improved RESET SLAVE (we now use less relay log files)
mysql-test/suite/rpl/r/rpl_stm_mix_show_relaylog_events.result:
  Updated results after improved RESET SLAVE (we now use less relay log files)
sql/log.cc:
  Added parameter to reset_logs() so that one can specify if new logs should be created.
sql/log.h:
  Added parameter to reset_logs()
sql/rpl_mi.cc:
  Create Master_info_index::index_file_names once at init
  More DBUG_PRINT
  Give error if Master_info_index::check_duplicate_master_info fails
sql/rpl_rli.cc:
  If we do a full reset, don't create any new relay log files.
sql/share/errmsg-utf8.txt:
  Improved error message if connection exists
sql/sql_parse.cc:
  Fixed memory leak
sql/sql_repl.cc:
  check_duplicate_master_info() now generates an error
  Added parameter to reset_logs()

sql/sql_parse.cc

@@ -2377,6 +2377,7 @@ case SQLCOM_PREPARE:
         work.
       */
       master_info_index->remove_master_info(&lex_mi->connection_name);
+      delete mi;
     }
 
     mysql_mutex_unlock(&LOCK_active_mi);