Failed release of master ticket blocks dependent encodings

[zuntrax]

When the state of a master ticket is set to "releasing failed", its dependent tickets are no longer offered to workers, for encoding, postencoding and postprocessing.

I think we should ignore errors in states after the minimum required state to start dependent tickets.

[a-tze]

Sounds right, but on the other hand sometimes we set tickets on "released failed" or "releasing failed" manually, to show the fact that something is wrong, but the content is published in some way. One aspect of doing this is exactly to stop dependent tickets from wasting ressources.

I would dislike to add more complexity, users are already confused enough about the internals. "Failed is failed, if something shall be done then fix it." seems more memorable to me.

[jjeising]

I like the current behaviour, too. As it was introduced as a new behaviour in #169 we should probably add a message in _status.html.php as documentation.