Remove Twisted web server Twisted web server is not used anymore and has been superseded by pyramid many years ago. Furthermore, our usage is not compatible with Python 3. So we drop the "etwist" sub-package. As a consequence, "all-in-one" configuration type gets dropped as it was Twisted-specific. We resurrect it in cubicweb/pyramid/config.py by only keeping options used by the "pyramid". Similarly, we introduce a AllInOneCreateHandler in cubicweb/pyramid/pyramidctl.py that is basically the one that lived in cubicweb/etwist/twctl.py and is used to create the "all-in-one" instance. Added a TODO here about "pyramid.ini" that could be generated at the end of bootstrap() method. In cubicweb/devtools/httptest.py, CubicWebServerTC is now equivalent to CubicWebWsgiTC and the latter is dropped.

3.26 (1 February 2018)
======================

New features
------------

* For ``pyramid`` instance configuration kind, logging is not handled anymore
  by CubicWeb but should be configured through ``development.ini`` file
  following https://docs.pylonsproject.org/projects/pyramid/en/latest/narr/logging.html.

Backwards incompatible changes
------------------------------

* CubicWebConfiguration method 'shared_dir' got dropped.