[PATCH] message_id from submit_sm_response on DLR's

Hi,

Proposed patch adds support for the "%w" key on DLR's, to get the message_id
from the SMSC on SMPP connections.

Explanation: When Kannel sends an MT over an SMPP connection, a submit_sm
PDU is sent. The carrier responds with a submit_sm_response, carrying a
"message_id" attribute. If we have  proper dlr-mask set, this event (the
carrier accepting the message) causes Kannel to hit the dlr-url (even if the
carrier's not sending DLR's).

After applying the patch, a new parameter %w could be added to the dlr-url,
which will be loaded with the message_id from the SMSC. This can be useful
to correlate sent messages with the carriers response.

Here's the patch:

http://www.magicom-bcn.net/kannel/smpp-response-message-id.patch

Regards,

Alejandro