BeanAdapter should support Map objects

BeanAdapter currently does not support the ability to wrap Maps, because it will fail to retrieve the correct getterMethod and setterMethod. My current usecase is that I have a TableView with tableData that consists of objects with path "value-of-type-map.subvalue". The following code should return John Doe in my opinion:

HashMap root = new HashMap();
HashMap child = new HashMap();
child.put("name", "John Doe");
root.put("child", child);
System.out.println(JSON.get(root, "child.name"));

I will provide a patch.