Clean up cache_control.js

The following patch contains some code convention fixes both Drupal and JS specific.

Some fixes.
* Pass Drupal.settings to Drupal.beaviors[b].attach, some code rely on this and might break (e.g. ajax.js)
* Declare all variables not to pollute global scope
* Make sure iteration is only done on objects own properties.
* Fix tabs, missing semicolon and spaces around + operator according to Drupal guidelines.

Thanks for a great module,
www.snellman.fi is now using it.