Improve use of constants in maze.js. Review URL: https://codereview.appspot.com/7383057
Improve use of constants in maze.js.
Review URL: https://codereview.appspot.com/7383057

git-svn-id: 2cf55447cea94972d775c94cce66c944ede0459c@675 c400ca83-b69d-9dd7-9705-49c6b8615e23

tjpalmer/blockly,jadonk/blockly-bonescript,tobyk100/blockly-trunk,Khan/blockly,tobyk100/blockly-trunk,tobyk100/blockly-trunk,tjpalmer/blockly,tobyk100/blockly-trunk,Khan/blockly,jadonk/blockly-bonescript