Improvements

[noxify]

While integrating the queue engine into our internal app, I mentioned the following:

• If queue.add() uses not the name which is specified in queue.register, you don't get a useful error message
• Throwing an error in the queue.register callback often results in an {"name": "UnknownError", "message": "[object Object]"} error object in the database record
  • maybe it makes sense to provide a new method job.markAs("<status>", {}) to provide a function to have full control
• drizzle v1 seems not to work out of the box ( already mentioned in Drizzle V1 Tests #47 )
• maybe it makes sense to add an optional logging for debug reasons, to see what is currently executing and where it fails