[FEATURE] Concatenate list fields

__Tasks:__

- [x] test coverage
- [x] gather feedback for my changes
- [x] submit changes to the documentation

__Informations:__

| Q             | A
| ------------- | ---
| Tests pass?   | yes
| Fixed tickets | parts of #129 
| Doc           | none
I personally tend to pass options as an array, jquery style:

````php
function __construct($fieldDescriptors, $name, array $options)
{
    $options = array_merge(array(
        'glue' => ' ',
        'disabled => false,
        'default' => false,
        // ...
    ), $options);
}
````

Like that the calling code is slimmer and more explanatory.