Patch which adds to a collection instantiates wrong type

[martypitt]

(Possibly related to #14)

Given:

public class Project implements Serializable {
    @Id
    String id;

    List<Story> stories = Lists.newArrayList();
}

applying the following patch:

[{"op":"add","path":"/stories/0","value":{"id":"story1420381381217.764656"}}]

I expect that an instance of Story is created, and added to the stories list. Instead, an instance of Project is created, and added to the stories list (which will later result in a casting exception)