Docs: Use celery -A proj consistently
Added ability to change task name generation behavior
Removed unnecessary self
Use app.gen_task_name everywhere & updated docs
ignore unknown events in consumer

Custom event types (not starting with either 'task-' or 'worker-') break Consumer, as it tries to split a `None` returned by state.event()
Merge branch 'malinoff/custom-gen_task_name'
Merge branch 'master' of github.com:celery/celery