Added az to core.  Users won't see it yet, since we don't yet have app
translations, but it will show up in translatewiki.

Review URL: https://codereview.appspot.com/31200043

git-svn-id: http://blockly.googlecode.com/svn/trunk@1511 c400ca83-b69d-9dd7-9705-49c6b8615e23