Use finish marker in the Maze 'while' block.
Review URL: https://codereview.appspot.com/9609045

git-svn-id: http://blockly.googlecode.com/svn/trunk@936 c400ca83-b69d-9dd7-9705-49c6b8615e23
Remove gridlines from maze, add buildings.
Review URL: https://codereview.appspot.com/9514046

git-svn-id: http://blockly.googlecode.com/svn/trunk@937 c400ca83-b69d-9dd7-9705-49c6b8615e23