Add new job event

Right now its not possible, to have an external database which contains published jobs as well as the matching returns, because a new job is not announced on the event_bus, only the returns are.

There is a '_minions' event when a new job is announced, but i dont get (yet) whats its for.

Announcing a new job with an event seems reasonable for users (like me), who do not rely on the job-cache on the salt-master (too many minions) but who  listen on the event_bus to act on specific events/returns to put them into a database or any other external data-structure which will keep data for a longer period of time or as a job-archive.

I already have a "matching" daemon that does the above. Currently it listens on the event_bus and acts on events with 'new_job' or '\d{20}' as tag. If its of any interest to salt, please let me know. I'll polish it a little and contribute it.