v2.15.0
update highlight.js to v11.11.1
Add updated icons
Upgade jQuery, as required by Mozilla review
bump version for release
fix typo
default.css: update list-style comments to match reality
Implement forgot-to-render check on Fastmail
upgrade a lot of URLs to https
replaced GGroups with GHDiscussions; removed support for Postbox and Inbox
Changed all file permissions to 644 (until Cygwin screws it up again...)
update the privacy policy to mention LaTeX rendering service; make LaTeX support off by default
Update colors for upgrade notification and forgot-to-render prompt