Added option to avoid default readline completion
Added option to avoid default readline completion

This could be usefull when no matches literally means that the
completer cannot suggest anything (e.g for integer option values).

landonb/argcomplete,lisongmin/argcomplete,douglas-larocca/argcomplete,neizod/argcomplete,landonb/argcomplete,neizod/argcomplete,kislyuk/argcomplete,lisongmin/argcomplete,douglas-larocca/argcomplete,kislyuk/argcomplete