Fix some syntax issues with message being part of the text that's generated.

TBR=neil.fraser@gmail.com
BUG=None

Review URL: https://codereview.appspot.com/7228050

git-svn-id: http://blockly.googlecode.com/svn/trunk@608 c400ca83-b69d-9dd7-9705-49c6b8615e23