JQuery bug with no option on genemu_jquerygeolocation

If you just use jquerygeolocation type with no option (no map, no extra field) like that:

```php
$form = $this->createFormBuilder()
        ->add('test', 'genemu_jquerygeolocation')
        ->getForm()
;
```

It will produce this js code:
```javascript
<script type="text/javascript">
    jQuery(document).ready(function($) {
        $field = $('#form_toto_address');

        $field.addresspicker({"elements":[]});

    });
</script>
```

It seems that jQuery dislike this empty array, and it produce a blank page with some js error on chrome:

```
Uncaught TypeError: Cannot call method 'appendChild' of undefined main.js:11
pe main.js:11
ff.(anonymous function).f main.js:18
(anonymous function) main.js:9

Uncaught TypeError: Cannot read property 'firstChild' of null chrome-extension://kkelicaakdanhinjdeammmilcgefonfh/js/jquery.js:35
c.props.for chrome-extension://kkelicaakdanhinjdeammmilcgefonfh/js/jquery.js:35
(anonymous function) chrome-extension://kkelicaakdanhinjdeammmilcgefonfh/js/jquery.js:37
(anonymous function) chrome-extension://kkelicaakdanhinjdeammmilcgefonfh/js/jquery.js:154

Uncaught TypeError: Cannot read property 'style' of null app_dev.php:37
Sfjs.load.window.location app_dev.php:37
(anonymous function) app_dev.php:37
xhr.onreadystatechange app_dev.php:37

Error in event handler for 'undefined': $ is not defined ReferenceError: $ is not defined
    at insertTooltip (chrome-extension://kkelicaakdanhinjdeammmilcgefonfh/js/content.js:57:21)
    at toggleTooltip (chrome-extension://kkelicaakdanhinjdeammmilcgefonfh/js/content.js:33:3)
    at chrome-extension://kkelicaakdanhinjdeammmilcgefonfh/js/content.js:26:2
    at miscellaneous_bindings:286:9
    at chrome.Event.dispatchToListener (event_bindings:387:21)
    at chrome.Event.dispatch_ (event_bindings:373:27)
    at chrome.Event.dispatch (event_bindings:393:17)
    at Object.chromeHidden.Port.dispatchOnMessage (miscellaneous_bindings:253:22) event_bindings:377

Uncaught TypeError: Cannot call method 'appendChild' of undefined main.js:11
pe main.js:11
ff.(anonymous function).f main.js:18
(anonymous function)
```

I simply separated `elements` from `configs` and test if array is not empty, works perfectly for me ! ;)

About configs, this type is not configurable at all, and a lot of new elements can be add as you can see here: https://github.com/sgruhier/jquery-addresspicker/blob/master/demos/index.html

Furthermore, the documentation has to be completed.

I will work on it soon.

Thanks. :)