Align behaviors between CLI and generators

Since the latest modification, Nuxeo CLI doesn't have the expected behavior when starting without args.

`nuxeo hotreload` must have the same behavior than `yo nuxeo:hotreload`; that corresponding to `yo nuxeo:hotreload configure`.

Changes occured since I changed the way to register commands (using commandDir yargs cmd).

• Arguments are the same, compared from `nuxeo bootstrap` and `yo nuxeo`.
• seems method `initializing` in any generators is no longer called without any param.