Changes to maze/, and common.js
A continuation of issue 10379048
Updates to UI:
-Reinforcements changed from separate pages to modal dialogs
-Language and avatar skin changes merged in from trunk.
-Provide feedback if maze solved but not in optimal way

R=neil.fraser@gmail.com, spertus@google.com

Review URL: https://codereview.appspot.com/11537043

git-svn-id: http://blockly.googlecode.com/svn/trunk@1119 c400ca83-b69d-9dd7-9705-49c6b8615e23