Since ChildAdded events originate from the CObject constructor, they are not
fully constructed when their parent learns that they were added.
Added a little comment about this to the child_event() declaration.
This macro goes at the top of every CObject-derived class like so:
class SomeClass : public CObject {
C_OBJECT(SomeClass)
public:
...
At the moment, all it does is create an override for the class_name() getter
but in the future this will be used to automatically insert member functions
into these classes.
