Static creation methods

Just some simple static methods to easily create a JSONObject from a Map, or a JSONArray from a List.

E.g. 
```java
final Map<String, Boolean> map = new HashMap<String, Boolean>();
// add some entries
final JSONObject object = JSONObject.fromMap(map);
```

Or
```java
final List<Double> list = new ArrayList<Double>();
// add some values
final JSONArray array = JSONArray.fromList(list);
```

It still maintains the same rules as before. (e.g. it will not allow creation of a JSONObject from a Map whose value types are not authorized)