Bug 867985 - update number of locales

We went from 89 to 80 locales. Amending the text to "over 70" and "more than 90%" is vague enough to be accurate for the foreseeable future even as the specific number fluctuates.
Firefox pages js should consider esr builds up to date bug 828064

tidy up

tidy up again

stick to js variable naming convention

update devices.js to include esr releases

Update template, l10n amends, minor JS tweaks

insert new line at EOF

remove local variables no longer needed

tidy up

remove old context_processors file post update
Bug 833534 Replace missing .visuallyhidden class
Merge pull request #860 from sgarrity/bug-833534-fix-video-close

Bug 833534 Add missing .visuallyhidden class
Merge pull request #863 from craigcook/bug-867985-update-15-facts

Bug 867985 - update number of locales
Fix bug 856075: Redirect technologies.html to MDN.
Add venv directory to gitignore.
Bug 868618 - Update Google Play store URLs

Changed from market.android.com... to play.google.com and verified the new URL format.
Merge pull request #879 from pmclanahan/chrismore-patch-8
Merge pull request #866 from alexgibson/firefox-page-js-consider-esr-up2date-bug-828064

Firefox pages JS should consider ESR builds up to date bug 828064
Merge pull request #864 from openjck/gitignore-venv
Merge pull request #865 from openjck/bug-856075-redirect-technologies
Remove older local submodules that are now in vendor.

* Update some out-of-date docs.
* Add upgrade instructions.
Merge pull request #880 from pmclanahan/remove-old-vendor-local-things