[fix bug 1053205] Missing Mozilla Montenegro from Contact Pages
Merge pull request #2232 from alexgibson/bug-1053205-montenegro-contact-pages

[fix bug 1053205] Missing Mozilla Montenegro from Contact Pages
Add docs for mozilla-accordion.js. Bug 1007717.

- Add GA tracking for accordion collapse event.
- Move ARIA from HTML to JS.
- Refactor mozilla-accordion.less to rely on new
  (non-ARIA) HTML hooks.
- Disallow direct child tabs - all accordion tabs/panels
  must be in a separate wrapper element.
Merge pull request #2234 from jpetto/bug-1007717-mozilla-accordion-js-docs

Add docs for mozilla-accordion.js. Bug 1007717.
Add PyYAML in support of bug 1026184.
Bug 1026184: Port /security to bedrock.
Drop Product table. Add last-modified header magic to views.