fixed onEdit / reading from e.event instead from data

Hi Sebastien,
could you please pull and have a look at onEdit() and SchedulerPayload?
```
// resources //
for (String field : SchedulerBehavior.this.getResourceListModel().getFields())
{
	parameters.add(CallbackParameter.resolved(field, "e.event." + field)); // retrieved
}
```
The parameter resolving code of onEdit() does not work for ResourceIDs, and I dont no why.


```
public SchedulerPayload(final ResourceListModel listModel)
{
        ...
	for (ResourceList list : listModel.getObject())
	{
		String field = list.getField();
		StringValue value = RequestCycleUtils.getQueryParameterValue(field);
        ...
```
```RequestCycleUtils.getQueryParameterValue(field)``` always returns a String.
It looks like an unevaluated json object ```[Object, Object]``` or something.

For DataSource-related events it works perfect.
There the resolving code looks the same, but just resolved from 'data', not 'event'.
```CallbackParameter.resolved(field, "e.data." + field)```.
There I get something like ```[1,2]``` in SchedulerPayload, which are correct ResourceIDs.

It seems to me ```Wicket.Ajax.ajax(attrs);``` behaves different on packing query parameters.
But I dont have much experience with ```Wicket.Ajax``` stuff.

thanx a lot
Patrick