初步翻译，待修改。
Merge branch 'master' of https://github.com/html5rocks/www.html5rocks.com
Updated href of broken font loading reference link.
Updated href of broken font loading reference link. (In the translated versions too.)
translate speed/layers
Add Opera support status to WebRTC Basic tutorial
Update Opera support status to WebRTC DataChannels and Infrastructure tutorials
Translated Navigation Timing tutorial as Korean

* "Measuring Page Load Speed with Navigation Timing"
Merge pull request #976 from richtr/webrtc_opera

Add Opera support status to WebRTC tutorials
Merge pull request #977 from cwdoh/article.ko.navigation-timing

Translated 'Navigation Timing' into Korean
Merge pull request #974 from pearlchen/promises-link-404

Updated href of broken font loading reference link.
Add Opera WebRTC support to database/tutorials.yaml
Merge pull request #975 from sunnylost/master

Translate speed/layers into Simplified Chinese
Merge pull request #978 from richtr/webrtc_db_opera_update

Add Opera WebRTC support to database/tutorials.yaml
Automatically updating the calendar
Automatically updating the calendar
Automatically updating the calendar
Automatically updating the calendar
Automatically updating the calendar
custom elements article: use http url