Fix colour field when compiled. Improve hint in Maze:7.

git-svn-id: http://blockly.googlecode.com/svn/trunk@1714 c400ca83-b69d-9dd7-9705-49c6b8615e23
Solve race condition on fast execution highlights.

git-svn-id: http://blockly.googlecode.com/svn/trunk@1715 c400ca83-b69d-9dd7-9705-49c6b8615e23