In their infinite wisdom, DPAG decided to require electronic advance
information about international shipments of goods ("Warenpost
International") but not offer that through the same API that one uses to
purchase the franking/postage ("Internetmarke API").
Instead, on has to implement talking to a completely different API
called AM.exchange. That API seems to be designed for really large-scale
customers to register mass mailings, distribution of magazines, etc.
To make things even more exciting, accessing that AM.exchange API
requires new user credentials, concluding new contracts,...
This commit adds the bulk of the functionality required to talk to
AM.exchange to provide customs-related information about shipments.
Contrary to Internetmarke-API, AM.exchange doesn't appear to be hosting
the WSDL definitions of its interface anywhere publicly. So instead, we
have to ship the WSDL files together with python-inema.
Prior to this commit, we useda custom modified versin of python-zeep
that accepts a list of headesr as part of the _soapheader argument.
Recent changes to python-zeep include that support natively using the
_soapeheaders [plural] argument. Port the code to that.
Harald Welte
Georg Sauthoff
Matthias Bilger