Template support

Based on cjstewart88s Template extension, with some improvements:
1. The templates are used for displaying not only in the dropdown, but also for selected values and the default values (basically everyhere a Option is displayed)
2. The Template gets handed the text and the value of an Option
3. Updated to work with the latest Version

# DOM
```htm
<select data-placeholder="Choose your favorite candy..." class="chzn-select-template-example" style="width:350px;" tabindex="11">
  <option value=""></option>
  <option data-type="chocolate" data-user-rating="1.8" value="sel1">M&Ms</option>
  <option data-type="fruity" data-user-rating="1" value="sel2">Starburst</option>
  <option data-type="fruity" data-user-rating="7" value="sel3">Skittles</option>
  <option data-type="chocolate" data-user-rating="9" value="sel4">Reese's</option>
  <option data-type="chocolate" data-user-rating="10" value="sel5">Snickers</option>
</select>
```
# Usage
```javascript
$(".chzn-select-template-example").chosen({
  template: function (text, value, templateData) {
    return text + " <i>type: " + templateData.type + "</i> value: " + value;
  }
});
```

# Result
![example page](https://f.cloud.github.com/assets/937467/43421/081f32cc-5686-11e2-9fe5-35b9a68fc020.png)


# More example usages (with customized CSS):
Single select:
![chosen_single](https://f.cloud.github.com/assets/937467/43363/9b66c4a4-5682-11e2-9128-bc5831f6d111.png)
Multi select:
![chosen_multi](https://f.cloud.github.com/assets/937467/43364/9b7f1220-5682-11e2-9b29-277ec7807b77.png)