Create register_class.rb
Update register_class.rb

native_call method implement
Create create_window.rb
test add.
Create wndclassex.rb
Update wndclassex.rb

initialize
wndclassex_spec.rb Add
Update wndclassex.rb

memorise args. (@args)
Update wndclassex.rb

Comment outed parameter descs
Update wndclassex.rb

def pack