Incorrect value being parsed 

For options with `multiple: false` and `defaultOption: true`, the first value parsed should be taken - not the last.

Say you have this option definition: 

```js
{ name: 'file', defaultOption:true }
```

And you run your example app this way:

```
$ example one.js two.js three.js
```

Then, in the output `file` should be set to `'one.js'`, not `'three.js'` (as it is currently).
