Description of problem:
When printing a test page, if it goes wrong and needs to be cancelled there is
no way to do that in the interface.  What's worse is that if the configuration
tool has been run in privileged mode, the user has no other means of cancelling
the job either.

Version-Release number of selected component (if applicable):
system-config-printer-0.7.35-1.fc6

How reproducible:
100%

Steps to Reproduce:
1.System->Administration->Printing
2.Look for a way to cancel it.
  
Actual results:
No way to do it.

Expected results:
Should be a way to cancel all test page jobs on that queue.

Additional info:
Perhaps the 'Print Test Page' button could be changed into a 'Cancel Tests'
button when there are test page jobs in the queue.