Bug 1084550: Flame Ads

Custom styles to support Flame ads macro. To test, copy https://developer.allizom.org/en-US/docs/Template:flame to your local dev and involk as {{flame(0)}} or {{flame(1)}}
bug 1072493 - Allow customizable domain runner via command line
Merge pull request #2839 from stephaniehobson/BUG-1084550-flame-ads

Bug 1084550: Flame Ads
Fix bug 1083463: Increase search letter-spacing
Merge pull request #2841 from darkwing/test-updates

bug 1072493 - Allow customizable domain runner via command line
Merge pull request #2834 from openjck/1083463-homepage-search-box-letter-spacing

Fix bug 1083463: Increase search letter-spacing
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
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.