Support setting class to select options

Setting class to select option is possible by giving 'inputclass' to source array:

    source: [
          {value: 1, text: 'Active', inputclass: 'active'},
          {value: 2, text: 'Blocked', inputclass: 'blocked'},
          {value: 3, text: 'Deleted', inputclass: 'deleted'}
    ]

Output:

     <option class="active" value="1">Active</option>
     <option class="blocked" value="2">Blocked</option>
     <option class="deleted" value="3">Deleted</option>