Update tutorials.yaml
merge upstream
Removes social from tutorials landing page
Updates appcache
update metadata
Merge branch 'master' into htmlimports-article
HTML Imports articles. Fixes #493 and #743
Merge branch 'master' of github.com:html5rocks/www.html5rocks.com
Moves high perf animations article
Cachebusts CSS
Merge pull request #744 from ebidel/htmlimports-article

HTML Imports articles
Update CALENDAR.md
Merge branch 'master' of github.com:html5rocks/www.html5rocks.com
Update CALENDAR.md
Update CALENDAR.md
Update CALENDAR.md
custom elements ko localization.

korean translate
add lost text

add lost text
Merge pull request #746 from ShinHyunjin/master

Korean translation "Custom Elements: defining new elements in HTML"