[NO_MERGE] Bug 801909: Port /credits and /credits/faq to bedrock.

* Add credits CSV file processing.
* Add FAQ and Credits templates.
* Add cron command for updating credits.csv from svn.

@jgmize r?

Not yet ready for merging though. @sgarrity probably wants to take this and make at least the FAQ page prettier.
My guess is that the styles are for non-Fx browsers? We can always bundle those styles up if we want, but the link to them would have to be absolute, and as it stands now there are no external assets on this page at all. I'm just unsure of the restrictions on a builtin page like this. Perhaps @gerv knows some of that history?