Description:
------------
Client doesn't receive data/status from workers when jobs 
are run in 
the background.

This was already mentioned by Rasmus back in 2009:
http://toys.lerdorf.com/archives/51-Playing-with-
Gearman.html

quote:
"I only use non-blocking background tasks and it currently 
isn't 
possible to use this data passing mechanism from a 
background task. 
Right now if you call $job->data() from a background worker, 
the 
data is simply dropped."

(see the 2 last paragraphs)

What's the status?

Is the problem with the Gearman server? or only the Pecl 
extensions?

Reproduce code:
---------------
On the client:

Register callbacks:
setDataCallback()
setStatusCallBack()

Add bg tasks:
addTaskBackground()
runTasks()

On the Worker:
sendData()
sendStatus()

Expected result:
----------------
When the worker calls sendData/sendStatus, the corresponding 
registered callbacks on the Client should be called

Actual result:
--------------
Callbacks not called, data dropped.