Created Unassigned: ValidatorCalloutExtender with static resources renders incorrect image references [27830]

In version 15.1, when a ValidatorCalloutExtender is used with default images and static resources (bundling) it renders image locations relative to the location used, rather than relative to the project. If this control is used in a subdirectory (e.g. in a UserControl in a subdirectory called UserControls), then the incorrect path is rendered (it should reference ~/Content/AjaxControlToolkit/Images/ but it references UserControls/Content/AjaxControlToolkit/Images/ and the images are not found).

For example:
```
Sys.Application.add_init(function() {
$create(Sys.Extended.UI.ValidatorCalloutBehavior, {"ClientStateFieldID":"ctl00_ctl00_BodyCPH_RepositoryFilter1_StartCompValCallout_ClientState","closeImageUrl":"UserControls/Content/AjaxControlToolkit/Images/ValidatorCallout.Close.gif","id":"ctl00_ctl00_BodyCPH_RepositoryFilter1_StartCompValCallout","warningIconImageUrl":"UserControls/Content/AjaxControlToolkit/Images/ValidatorCallout.Alert-Large.gif"}, null, null, $get("ctl00_ctl00_BodyCPH_RepositoryFilter1_StartComp"));
});
```