list of files and directories at remote server
        :param href: remote folder
        :return: list(folders, files) and list(None,None) if folder doesn't exist

def list(self, href):
        """
        list of files and directories at remote server
        :param href: remote folder
        :return: list(folders, files) and list(None,None) if folder doesn't exist
        """
        for iTry in range(TRYINGS):
            logger.info(u("list(%s): %s") % (iTry, href))
            folders = None
            files = None
            try:
                href = os.path.join(u("/"), _(href))
                conn = self.getConnection()
                conn.request("PROPFIND", _encode_utf8(href), u(""), self.getHeaders())
                response = conn.getresponse()
                checkResponse(response)
                data = response.read()
                if data == b('list: folder was not found'):
                    return folders, files
                elif data == b('You are not authorized to see this!'):
                    return folders, files
                else:
                    try:
                        dom = xml.dom.minidom.parseString(data)
                        responces = dom.getElementsByTagNameNS("DAV:", "response")
                        folders = {}
                        files = {}
                        for dom in responces:
                            response = RemoteObject(dom, self, href)
                            if response.href != href:
                                if response.isFolder():
                                    folders[response.href] = response
                                else:
                                    files[response.href] = response
                    except xml.parsers.expat.ExpatError:
                        e = sys.exc_info()[1]
                        logger.exception(e)
                return folders, files
            except ConnectionException:
                raise
            except Exception:
                e = sys.exc_info()[1]
                logger.exception(e)
            return folders, files