Added more common interface functionality to JSONNode.java.
Added exception throwing for some of the overridden methods in JSONNode.java.
Changed count() to size() to conform to Java's List class.
Added various @Override statements to correctly override inherited functions.
Added an @Override and more descriptive error messages.
Made some overridden methods throw JSONAccessException so that the methods overriding it can be fancy and throw as many exceptions as they please.
Added some basic functionality to JSONClass.java.