Update index and demo page for new simplified optionsItemBuilder API

Author: lcdsantos

public/index.html

@@ -704,8 +704,8 @@ <h4><a href="./demo.html">view more advanced demos and customization →</a></h4
   <script>
     $(function() {
       $('.customOptions').selectric({
-        optionsItemBuilder: function(itemData, element, index) {
-          return element.val().length ? '<span class="ico ico-' + element.val() +  '"></span>' + itemData.text : itemData.text;
+        optionsItemBuilder: function(itemData) {
+          return itemData.value.length ? '<span class="ico ico-' + itemData.value +  '"></span>' + itemData.text : itemData.text;
         }
       });
 

public/lib/demo.js

@@ -241,9 +241,9 @@
     /*------------------------------------*/
 
     $('.custom-options').selectric({
-      optionsItemBuilder: function(itemData, element, index) {
-        return element.val().length ?
-          '<span class="ico ico-' + element.val() +  '"></span>' + itemData.text :
+      optionsItemBuilder: function(itemData) {
+        return itemData.value.length ?
+          '<span class="ico ico-' + itemData.value +  '"></span>' + itemData.text :
           itemData.text;
       }
     });