* @param string $request request url
* @param integer $uid User id of the requester
* @param boolean $binary TRUE if asked to return binary results (file download) (default is "false")
* @param string $request request url
* @param integer $uid User id of the requester
* @param boolean $binary TRUE if asked to return binary results (file download) (default is "false")
* 'accept_content' => supply Accept: header with 'accept_content' as the value
* 'timeout' => int Timeout in seconds, default system config value or 60 seconds
* 'nobody' => only return the header
* 'accept_content' => supply Accept: header with 'accept_content' as the value
* 'timeout' => int Timeout in seconds, default system config value or 60 seconds
* 'nobody' => only return the header