A bunch of small changes

those are all small changes that I didn't bother branch each, hope it's ok:

1. re-adding gtid related events: for some reason those were removed. If GTID is enabled (mysql 5.6+) those events are fired and exceptions are raised

2. Added comment about running tests - how to configure your mysql - otherwise the tests will get stuck forever (no events are thrown) and this can be frustrating for a first time user

3. disable reporting on non implemented events to help testing - our tests are very delicate and depend on specific events beings thrown - in several cases other events are thrown as well - we usually want notimplemented events not to be thrown around