Provide better and more general UI for realtime authorization.
Fixes issue 206.
Fixes issue 207.

R=neil.fraser@gmail.com

Review URL: https://codereview.appspot.com/60830043

git-svn-id: http://blockly.googlecode.com/svn/trunk@1633 c400ca83-b69d-9dd7-9705-49c6b8615e23
Forgot to include msg/messages.js in my last commit!

git-svn-id: http://blockly.googlecode.com/svn/trunk@1635 c400ca83-b69d-9dd7-9705-49c6b8615e23