Bug 1070001: Re-org Stylus - demo studio

Moved the demo studio CSS into the redesign folder.
Broke CSS into smaller files using the existing comments as a guide. Some of these are components, the way I want to organize files in the future, but some of them are not. Weird mish-mash, sorry.
Merge pull request #2842 from stephaniehobson/BUG-1070001-reorg-stylus-demos

Bug 1070001: Re-org Stylus - demo studio
bug 1087015 - Improve demo studio homepage's mobile display
fix bug 899665 - add change update subscription link for parents of translated pages
Merge pull request #2838 from jezdez/bug899665

fix bug 899665 - add change update subscription link for parents of translated pages
Merge pull request #2844 from darkwing/1087015-redesign-demo

bug 1087015 - Improve demo studio homepage's mobile display
Fix Bug 1087020: Demo deatil page mobile view

Added clearfix() to mobile column declaration, this could break stuff.
BUG 1084110: Upgrade Stylus & Clean CSS

All ways good to have most recent versions of things both updates inclue bug fixes and the Clean CSS one saves us yet more white space.

Small change to the font-awesome.styl file to remove an unnecissary call that was throwing new Stylus into an infinate loop.
Bug 1082853: Configure CSSLint and validate MDN CSS

Made a more decerning vendorize mixin with lookup tables for values.
Made a mixin for creating rgba fallbacks.
Remove table.activity which was presumably added back in during a merge somewhere).
Validate CSS, mostly working with outlines.
Bug 1083889: Manually activate Optimizely test
Merge pull request #2851 from openjck/1083889-manually-trigger-sticky-button-test

Bug 1083889: Manually activate Optimizely test
Merge pull request #2849 from stephaniehobson/BUG-1084110-upgrade-stylus

FIX BUG 1084110: Upgrade Stylus & Clean CSS
bug 916229 - proposing a patch to fix the bug
Merge remote-tracking branch 'mozilla/master' into bug916229
bug 916229 - formatting sql queries and adding {% trans %} block
Merge pull request #2848 from stephaniehobson/BUG-1087020-demo-detail-page

Fix Bug 1087020: Demo detail page mobile view
bug 916229 - moving the querying into Celery task
bug 1084110 - Update paths to stylus and cleancss
Merge pull request #2854 from darkwing/update-stylus-location

bug 1084110 - Update paths to stylus and cleancss
BUG 1087015: Demos - menu

Fix "browse by technology" menu being open by default.