Rename Blockly.editable to Blockly.readOnly (matches the configuration parameter), and apply this setting to squelch more functionality.  Add Block.editable which squelches a block's fields.  Now that readOlny works properly, remove 'notouch' layer from Puzzle help.

R=spertus@google.com

Review URL: https://codereview.appspot.com/12173043

git-svn-id: http://blockly.googlecode.com/svn/trunk@1170 c400ca83-b69d-9dd7-9705-49c6b8615e23