Koji patches for review

[Ken Dreyer]

I've got a few patches lined up for Koji, and I'd love to see them get
reviewed and merged. I'm happy to answer any questions about them.
(Please also let me know if there is a more appropriate avenue to get
these reviewed and merged.)

https://fedorahosted.org/koji/ticket/224 Avoid pgdb's _quoteparams()
https://fedorahosted.org/koji/ticket/227 fix pkgorigins.gz file creation in F16
These two are necessary to make Koji work on Fedora 16.

https://fedorahosted.org/koji/ticket/225 better examples for Kerberos
auth options
This is essentially a doc fix, should be really simple.

https://fedorahosted.org/koji/ticket/229 make SCM URL validity check
more verbose
This is an attempt to make the errors more helpful when Koji can't
understand the user's SCM URL. As a Koji newbie it was difficult for
me to figure out the precise SCM string format that Koji expects;
these error messages helped me troubleshoot my way through the fog.

The next two are "bigger" logic changes.

https://fedorahosted.org/koji/ticket/226 Don't rewrite HTTPS URLs as HTTP
This is a tweak to Koji-web so that I don't get kicked back to an HTTP
URL when I click "logout".

https://fedorahosted.org/koji/ticket/230 add HTTP "proxy" option to builder
This is a feature that implements an HTTP proxy option for the
builders. It allows me to easily use my Squid box as a cache so I
don't have to hit a mirror over the internet each time. This mailing
list thread from 2008 was the inspiration:
https://lists.fedoraproject.org/pipermail/buildsys/2008-November/002271.html

- Ken