Simplified a log string
Bugfix in read_queue_tree: NULL -> None
Implement assign_agents_to_job()
Removed now unused agents_with_tasks_at_prio()
Removed now unused get_batch_agent_pair()
Bugfix in assign_agents_by_weight(): put in list
Don't set job state in assign_agents_to_queue()

We now do that in assign_agents_to_job
Bugfix in assign_agents_to_queue()