This is a useful debugging function for developers. It is enough to hide
the menu by default on stable releases, I don't think we also need to
hide the CLI option. Developers don't know all these options by heart,
so we need to make them reasonably discoverable!
In particular make it also work with the `gimp-console` and with all
symlink names.
Also rename the bash completion file using the full application version
so that it will be possible to install several such completion files
side by side.