- changes for async and sync http-requests
* timeout is now the per-io-operation timeout
and not the timeout for the whole requests
(hardly predictible for internet transfers)
* non-blocking POST requests for large POST data
* the notification_handler has now an extensive
list of response methods: deliver, done, success, failure,
start_request, request_data, start_reply, reply_data
It should be possible to provde progress bars for
GET and POST requests