flake8
passed.
JSHint
passed.
Add additional HTTP status codes to the :http: role.
Review Request #9225 — Created Sept. 27, 2017 and submitted
This adds a handful of HTTP codes we didn't have before. Some are
officially standardized, while others were introduced by WebDAV or
certain web servers and are now "claimed" by those.
Made use of one of the codes in some release notes successfully.
