Emit a single event where the first argument contains
a "JobEvent" enumeration that describes the particular
event. This reduces the number of callbacks registered
by JobState consumers and allows them react to multiple
state changes in the same callback.
The individual events remain for compatibility, however
they are deprecated. Current modules should be updated
to use the "job_state:state_changed" event and new modules
must use this event.
Signed-off-by: Eric Callahan <arksine.code@gmail.com>
