Add release notes for Review Board 2.5.8.
Review Request #8727 — Created Feb. 8, 2017 and submitted — Latest diff uploaded
This is a pretty big release with a large number of bug fixes, usability improvements, configuring improvements, and some new features. This change details the release notes for all these additions going into 2.5.8.
Built the docs and read through them, checking links.
Checked for spelling errors.