Add language menu to apps/index.html.
Add Russian translation of index page.
TODO: Add RTL support for index page.

R=neil.fraser@gmail.com

Review URL: https://codereview.appspot.com/22220046

git-svn-id: http://blockly.googlecode.com/svn/trunk@1479 c400ca83-b69d-9dd7-9705-49c6b8615e23