Nested forloop support in template

[suresh-gangumalla]

These changes in code-generator handles nested for-loop scenario in template.

<Element :for="(item, index) in $data" key="$item.id">
    <!-- template that handles $item first level data -->
    <Element :for="(item1, index1) in $item.list" key="$item1.id">
       <!-- template that handles $item1 information -->
       <Element :for="(item2, index2) in $item1.list" key="$item2.id">
          <!-- template that handles $item2 information -->
      </Element>
   </Element>
</Element>