Description of problem:
There are some printers complaining when printing using ipp backend (URI ipp://printer-address/ipp).
E.g. Epson AL-CX11NF is showing 'Processing' although the job has already finished and the printer is ready.
(see bug#260961, comment #12)
Or Canon iR 3170C claims there's some printer error when printing, but the page
is printed perfectly. (see bug#518065, comment #5)
Both have other-warning in printer-state-reasons. 

The work-around for this is to add ?waitjob=false option to device URI so
it looks like ipp://printer-address/ipp?waitjob=false

The ipp backend supports many options, which are summarized in
http://www.cups.org/documentation.php/doc-1.4/network.html#TABLE2

If these problems are really on the printer side (they do not implement IPP properly)
there should be some check-boxes in system-config-printer for these options.

See also
http://www.cups.org/str.php?L699
"It is sometimes desirable to treat print jobs to ipp printers 
as successfully completed already if the job submission has been successful, 
e.g. because the printer is essentially a queue defined on a production printer, 
and the detailed schedules on that machine are controlled by a person 
or software other than CUPS."

Version-Release number of selected component (if applicable):
cups 1.3 or 1.4
system-config-printer any version

How reproducible:
always

Steps to Reproduce:
1. Set the queue for Epson AL-CX11NF or Canon iR 3170C with URI ipp://printer-address/ipp
2. print test page
  
Actual results:
Epson AL-CX11NF is showing 'Processing' although the job has already finished and the printer is ready.
Canon iR 3170C claims there's some printer error when printing.
In both cases the page is printed perfectly but
both printers have other-warning in printer-state-reasons. 

Expected results:
No false alarms.