Wildcard support for job processing

I didn't see this in old issues, so I just want to propose it:

```
queue.process('notifications:*', function (job, done) {
email(job.data.to, done)
})
```

Alternatively, any idea about getting a similar approach with the existing features?

Start at the queue.process entry point and trace how named jobs are currently matched and dispatched. Check the existing processing behavior before deciding how wildcard patterns should interact with exact names; done means a pattern such as notifications:* consistently selects the intended jobs without breaking existing processing.

Written by the indexing model from the issue text.