Add a simple gnt-job script

Add a simple gnt-job script

This patch adds a very basic gnt-job script that allows job querying.
This goes on top of the previous master daemon patches.

Currently, because of the not-changed cmd lock, you can't query the jobs
as long as a job is running - you have to rm the cmd lock and then you
can query the jobs.

Reviewed-by: imsnah