translate weird python underscored keys into dashed argv, avoiding single character aliases.
function dasherizeShorthands(hash) {
    // operate in-place
    Object.keys(hash).forEach(function(key) {
        // each key value is an array
        var val = hash[key][0];
        // only dasherize one-character shorthands
        if (key.length === 1 && val.indexOf('_') > -1) {
            hash[dasherizeFlag(val)] = val;
        }
    });

    return hash;
}