[pyramid] Let logging be configured through .ini file
We do not initialize logging in CubicWebPyramidConfiguration thus preventing logging to be started with cubicweb's configuration. On the other hand, any logging configuration defined in ``development.ini`` file will be loaded by whatever start the instance using this file (i.e. pserve, gunicorn, etc.). The benefit is that logging can now be configured per "qualified name" in this file (i.e. one can easily set the DEBUG level for the application cube while keeping all dependencies' level to WARNING). In the development.ini template, we add logger configurations for "logilab" and "cubicweb" qualified names (along with those of the application cube).