* Refactor osg::cvmfs to use anchor pattern
* Rename http_proxy parameter to http_proxies which now expects an Array
* Change default value for http_proxy (now http_proxies) to be ['http://squid.${::domain}:3128']
* Rename server_url parameter to server_urls which now must be an Array
* Fix incorrect default server_url (now server_urls) that lacked the "@org@" piece of URL