Allow user to specify https or https protocol for AJAX calls

This enhancement allows the developer to force AJAX connections to use http://, https://, or auto-detect based on the protocol of the current URL. It can be useful when jQuery Socialist is embedded on an https:// page; some browsers will fail to retrieve the Google Feed API using an http:// URL.

This is accomplished by adding a "secure" property in the networks config, as such:

    $('#socialist').socialist({
        networks: [
            { name:'rss', id:'http://www.rssfeedurl.com/', secure:true }
        ]
    });
        
Possible values for 'secure' are: true, false, "detect". If 'secure' is not specified, then it defaults to whatever protocol is set in the networkDefs object.