[debian] Install cubicweb-ctl from python2 build Previously, the binary package was empty. Now it is bound to the python2 package as support for python3 is "fresh". In order python2 and python3 packages to be co-installable, we drop the cubicweb-ctl file from both packages.

[debian] Introduce python3-cubicweb and python3-cubicweb-pyramid binary packages This is the bare minimum to have a working cubicweb on python3. Further work is done in default branch.