add additional data for source link urls with dynamic data

with this you have at least the option to add additonal data discussed https://github.com/vitalets/x-editable-yii/issues/40

e.g. by adding options like below
```
'additional_data' => array(
   'project_status_id' => '$data->project_status_id', 
   'version' => '$data->version',
   'test'=>'array($data->version,$data->project_status_id)',
),
```

then you have the possibility to access them in the source js code with e.g. $(this).data.version 
```
'source'    => 'js: function() {
                     var status_id=$(this).data().value;
                     var version=$(this).data().version;
                     var pk=$(this).data().pk;
                     return "?r=projectdetails/getProjectStatusList&status_id="+status_id+"&pk="+pk+"&version="+version;
            }',
```

the next step would be to automate the generation of the source url somehow.