Add jQuery scoping to prevent conflit with $ var

Hi,

I use pickadate in an environment where we also use Prototypejs (http://prototypejs.org/).
Prototype makes use of $ as main API var, as jQuery does.

The picker lib actually scope jQuery to $ but the translations are not. Translations js are making use of $ without scoping.

This patch fix that by wrapping each translation code in the pattern.

```javascript
(function($) {
    // translation code
})(jQuery);
```

Thanks.