[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.
The background-color and body text colors seem to already be set in the included ```chrome://global/skin/about.css``` file. Though maybe these are for some legacy issue.

Except for the text-align: center on the h1, these inline styles seem to be redundant.