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 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
Merge pull request #1248 from pascalchevrel/Bug-900493-homepage_redirect_update_l10n

Bug 900493: activate /new page for ta and son locales
Merge pull request #1247 from flodolo/kk_plugincheck

Bug 892470: enable plugincheck redirect for kk
Bug 900493: enable firefox/new redirect for kk
Merge pull request #1250 from flodolo/new_kk2

Bug 900493: enable firefox/new redirect for kk
Merge pull request #1245 from craigcook/bug-916928-update-flicks-promo

Fix bug 916928 - update flicks promo for winners
Merge pull request #1240 from alexgibson/bug-914328-add-firefox-os-screenshots

[bug 914328] Update Firefox OS Maps screenshots for DE, HU
Merge pull request #1225 from alexgibson/bug-913435-formatting-tweaks-email-newsletter-recovery-page

[Fix bug 913435] Formatting tweaks for Email newsletter recovery page
Merge pull request #1216 from pmclanahan/add-line-length-check

Add line length checking to flake8.
Bug 900493: enable firefox/new redirect for zh-CN
Bug 892470: enable plugincheck redirect for zh-CN
Merge pull request #1252 from flodolo/zhcn_new

Bug 900493: enable firefox/new redirect for zh-CN
Merge pull request #1253 from flodolo/zhcn_plugincheck

Bug 892470: enable plugincheck redirect for zh-CN
[fix bug 916190] Formatting tweaks for instant success message