Restores Maze.isPath{Left,Right,Forward,Backward}.

Review URL: https://codereview.appspot.com/14123044

git-svn-id: http://blockly.googlecode.com/svn/trunk@1387 c400ca83-b69d-9dd7-9705-49c6b8615e23
Added instructions for generating language files.
Changed common.read_json_file to ignore @metadata.
Removed obsolete key-value pair from vi.json.

R=neil.fraser@gmail.com

Review URL: https://codereview.appspot.com/14112043

git-svn-id: http://blockly.googlecode.com/svn/trunk@1388 c400ca83-b69d-9dd7-9705-49c6b8615e23
Fix multitude of IE bugs.  Fix tooltip on math_on_list.  Remove last JS from Maze template.

R=spertus@google.com

Review URL: https://codereview.appspot.com/14157043

git-svn-id: http://blockly.googlecode.com/svn/trunk@1389 c400ca83-b69d-9dd7-9705-49c6b8615e23