Feature: Validation & Input Filter UI Enhancements

Done:
 - [x] Jquery UI added
 - [x] sortable added
 - [x] select2 added
 - [x] input_filter added to api model
 - [x] Rest & Rpc screens include input tab
 - [x] input tab links to a service-input controller & view

Todo:
  - [x] Ensure RPC service can handle new HAL formats:

```
Fatal error: Class 'ZF\Apigility\Admin\Model\HalResource' not found in
...zf-apigility-admin/src/ZF/Apigility/Admin/Model/RpcServiceResource.php on line 268
```