Fix issue 132, issue 133, and issue 134:
* Variable set block has broken context menu.
* Comment in child block of collapsed parent.
* Procedure renaming to blank bug.
Review URL: https://codereview.appspot.com/8242045

git-svn-id: http://blockly.googlecode.com/svn/trunk@726 c400ca83-b69d-9dd7-9705-49c6b8615e23