Completes SC.ListItemView implementation by adding right icon on click action/target handlers

The standard SC.ListItemView supports displaying an optional icon on the right side.
Looking at the code it is quite clear that the icon was initially conceived as an active control (it has toggable active state) but there is no way to handle the state transition in application code.

This pull request completes the implementation by adding support for two new options on SC.CollectionView:

```
rightIconAction: "zoomToFeature"
rightIconTarget: "App.MyController"
```

so that the appropriate event can be fired when the right icon is toggled.
The new options appear in SC.CollectionView and have been properly documented.

The pull request includes, as customary, unit tests for the new behaviour.