session
In order not to leak these into other sessions, one keeps a registry
around as a session option. This will cascade into the request and
response encoding routines.
during the typing sessions, it was clear that there was some confusion
around the decoder/encoder concept as well as API convolution, i.e. zlib
implementation details leaked to the main compression module.
Therefore, interfaces for Deflater/Inflater were build from the ground
up, and the modules were rewritten accordingly.
