IPP

Did a little more hacking on my IPP client library, and wrote a small PyGTK program that lets you do simple management tasks (view all print queues/classes, view queued and completed jobs for printers, stop and start print queues, etc).

If you want to try it out, grab ipplib.py and printerlist.py. Put them in the same directory and run "python printerlist.py". Seems to work pretty well for less than a thousand lines of code.

To get things working with CUPS's authentication, I do the following for operations like Pause-Printer:

1. Submit request to the HTTP URI corresponding to the IPP one.
2. If the response has an IPP status code of client-error-not-authorized, then resubmit the request to the URI /admin/ relative to the previous URI (not changing the IPP message).
3. Return the IPP response message.

This seems to work quite reliably, so I might add the fallback to all the IPP requests.