Increased some tests' robustness a bit :
- Added RESET MASTER to all tests who do SHOW BINLOG EVENTS, to make them independent from previous tests.
- Added save_master_pos to these tests to wait for the slave to start before purging its binary logs.


mysql-test/r/rpl_log.result:
  Updated SHOW BINLOG EVENTS's positions as Monty lengthened std_data/words.dat by 500 bytes.
mysql-test/r/rpl_temporary.result:
  Added RESET MASTER to make positions shown by SHOW BINLOG EVENTS independent of any previous test.
mysql-test/r/rpl_user_variables.result:
  Added RESET MASTER to make positions shown by SHOW BINLOG EVENTS independent of any previous test.
mysql-test/t/rpl_log.test:
  Added save_master_pos to wait for the slave to have started before purging its binary logs.
  Otherwise, we could purge before the slave finishes starting, and then the slave could log events implicitly provoked by previous tests.
mysql-test/t/rpl_temporary.test:
  Added RESET MASTER to make positions shown by SHOW BINLOG EVENTS independent of any previous test.
mysql-test/t/rpl_user_variables.test:
  Added RESET MASTER to make positions shown by SHOW BINLOG EVENTS independent of any previous test.
BitKeeper/etc/logging_ok:
  Logging to logging@openlogging.org accepted