Manual rescheduling enqueues multiple jobs

[jspricke]

Thanks for #194 I can now schedule temporary packages faster again but it does not check if there is the same package in a different suite already present in the queue. I think it should use has_queued_friend(). Also one those multiple jobs finished with bad they are all scheduled again so there is probably an other case where checking for friends is missing.

[jspricke]

An other option would be to support specifying the release when scheduling.