[ctl] Load available configurations in "cubicweb-ctl list" Otherwise we rely on associated ctl plugins to be loaded which is arguably orthogonal to configurations.

[skeleton] Set cubicweb.bwcompat to False in development.ini Quite a few things from the default web UI do not work when running the application through pserve (in particular, data files are not apparently served). So better disable the "bwcompat" mode until we are sure it works properly (or it gets dropped ;)).