When calling an option by long form, it is possible to abbreviate its
name, at the risk of being ambiguous. An abbreviation is simply the
beginning of the option’s name (for instance, ‘--he’ can stand for
‘--help’). In case of ambiguity, Clon always chooses the option
which is “closest” to the abbreviation (here, the “distance” between
an abbreviation and an option’s name is the number of missing
characters).