Swap wall-detection to path-detection in maze app.

git-svn-id: http://blockly.googlecode.com/svn/trunk@659 c400ca83-b69d-9dd7-9705-49c6b8615e23
Update maze vn language accordingly.

git-svn-id: http://blockly.googlecode.com/svn/trunk@660 c400ca83-b69d-9dd7-9705-49c6b8615e23
Add speech bubble to Pegman.

git-svn-id: http://blockly.googlecode.com/svn/trunk@661 c400ca83-b69d-9dd7-9705-49c6b8615e23