CON-1888: Support for galleries

Conflicts:
	extensions/wikia/Venus/styles/article/article.scss
CON-1888: Typo
CON-1888: Added styles for galleries, sliders, slideshows and videos

Conflicts:
	extensions/wikia/Venus/styles/article/article.scss
CON-1888: Changes after design review
CON-1888: Prepare for galleries
CON-1888: Fix for old galleries
CON-1888: Removed file extension
CON-1888: Changes after CR
CON-1888: Use grid mixins only
CON-1888: Support bucky group
Merge branch 'CON-1888-galleries' into CON-NewArticle

Conflicts:
	extensions/wikia/AssetsManager/configGroups/VenusConfig.php
	extensions/wikia/Venus/styles/article/article.scss
	extensions/wikia/Venus/styles/article/images.scss
	extensions/wikia/Venus/styles/article/media.scss
	extensions/wikia/Venus/styles/article/video.scss