Load JS files from protocol-relative URI.

The [WordPress Developer plugin](http://wordpress.org/plugins/developer/) complained of "https" used in the `concat_script_tag` inside `wistia-anti-mangler.php`. Changing to a protocol-relative URI fixes the issue of trying to determine if SSL is active on a server by letting the browser take care of the loading for us.

Also: 

* normalized line endings in the main plugin (couldn't avoid this one. sorry for the massive diff!)
* tested against WP 3.6.1
* version bump to 0.6.1