First step towards X86-64 compatibility.

	First step towards X86-64 compatibility.
	* archive_tar.cc (archive_tar::next_file_name): Fix sscanf formats
	for 64-bit size_t.
	* choose.cc (ChooserPage::OnMouseWheel): Fix return type.
	* choose.h (ChooserPage::OnMouseWheel): Ditto.
	* filemanip.cc (nt_wfopen): Fix argument cast for _open_osfhandle.
	* netio.cc (auth_proc): Fix return type.
	* proppage.cc (PropertyPage::FirstDialogProcReflector): Fix return type.
	Use SetWindowLongPtr and DWLP_* instead of SetWindowLong and DWL_*.
	(PropertyPage::DialogProcReflector): Ditto.
	(PropertyPage::DialogProc): Ditto.
	(PropertyPage::OnMouseWheel): Ditto.
	* proppage.h (PropertyPage::FirstDialogProcReflector): Fix return type.
	(PropertyPage::DialogProcReflector): Ditto.
	(PropertyPage::DialogProc): Ditto.
	(PropertyPage::OnMouseWheel): Ditto.
	* site.cc (drop_proc): Fix return type.
	* window.cc (Window::FirstWindowProcReflector): Use GWLP_* with
	SetWindowLongPtr calls.
	(Window::WindowProcReflector): Ditto.