* like array("header" => "value")
* - cookies: array, list of cookies as associative array
* like array("cookie" => "value")
+ * - encodecookies: bool, whether to urlencode the cookies (default: true)
+ * - resetcookies: bool, wheter to reset the cookies
* - cookiestore: string, path to a file where cookies are/will be stored
* - resume: int, byte offset to start the download from;
* if the server supports ranges