Bug 916151 - home page redesign

Bug 916151: Enable home page template switch with query.

Bug 904696: Update home view to support l10n.
Add line length checking to flake8.

Throws warnings at 150 characters. Anything beyond that
in a python file is a bit over the top.

Also clean up the grants data a lot.
[Fix bug 913435] Formatting tweaks for Email newsletter recovery page
[bug 914328] Update Firefox OS Maps screenshots for DE, HU
Bug 868182: Fix FxOS faq redirect.
Fix bug 867764 Finish moving /newsletter/updated to Bedrock

* Update rewrite rule to match all locales
* Tweak message to catch already-translated text
Fix bug 916928 - update flicks promo for winners
Bug 868199: Update /new page.

Adds better user-agent custom messages, cleaned up images and Google
Analytics tracking.

See https://bugzilla.mozilla.org/show_bug.cgi?id=868199

 - custom messaging support for Desktop
   - non-Firefox
   - Firefox old
   - Firefox up-to-date
 - custom messaging support for Android
   - non-Firefox
   - Firefox old
   - Firefox up-to-date
 - custom messaging support for Firefox OS, informative links
 - custom messaging support for iOS, friendly unsupported message
 - improved screenshots
   - less locale-dependent
   - more platform-specific
 - added Google Analytics custom tracking
   - off-site links
   - custom var for platform reporting
 - fix media-query css for l10n-specific CSS
Bug 868199: Switch mobile links to use url helper.
Bug 892470: enable plugincheck redirect for kk
Bug 900493: activate /new page for ta and son locales
Bug 900493: enable firefox/new redirect for kk
Responsification, refactoring some JS, adding B2 stub