[debian] Update description of cubicweb-ctl* packages init scripts are no longer shipped. Avoid mentionning "start" and "stop" command which should not be used in production environments.

[debian] Introduce a cubicweb-ctl3 binary package This packages conflicts with cubicweb-ctl binary which uses the python2 library. It is meant to ease upgrade of existing installation during the migration from python2 to python3: in particular, by installing cubicweb-ctl3, scripts calling "cubicweb-ctl" command should still work as before.

[cubicweb-ctl] respect sys.exit status code when aborting a command When exploring the stack of all calls to a cubicweb-ctl command, it has been discovered than on a KeyboardInterrupt and on a SystemExit exception the base class InstanceCommand (for commands that works on one instance) will always set the return code of cubicweb-ctl to 8: this mean that if another command do a `sys.exit(some_code)` the exit code will be ignored and overwritten by '8'. This behavior is not intuitive, apparently not documented and doesn't seems to have any justification. It also prevent commands from exciting with different return codes which could be a desired behavior in the situation of scripting.

[test] Add an "actionverb" attribute to test commands