-------------------------------------------------------- Class#inherited
     inherited(subclass)
------------------------------------------------------------------------
     Callback invoked whenever a subclass of the current class is
     created.

     Example:

        class Foo
           def self.inherited(subclass)
              puts "New subclass: #{subclass}"
           end
        end
     
        class Bar < Foo
        end
     
        class Baz < Bar
        end

     produces:

        New subclass: Bar
        New subclass: Baz