Notification on status change.

[gugod]

I wish to be notified only when status is changed. For example, consider this build history:

1. Success
2. Success
3. Success
4. Fail
5. Fail
6. Success
7. Success

The notification should sent at build number 4 (Success -> Fail) and number 6 (Fail -> Success).

Besides this, with the current implementation, each notifier decides the timing of notification on their own, commonly with these attributes:

• ignore_success
• ignore_skip

This leads to some code duplication in each notifier module.

This new logic of "reporting on status change" can obviously be added to all notification mdules but that'll just make the code duplication even worse. It is perhaps better to add a role that decides when to notify or not.