Don't disable warning C4996 as that is the Visual C++ warning triggered by
__declspec(deprecated) and __declspec(deprecated('..."))-disabling that
warning will defeat the purpose of G_DPRECATED/G_DEPRECATED_FOR.

For people who don't want to see the GLib deprecation warnings during GLib
compilation, define GLIB_DISABLE_DEPRECATION_WARNINGS in the projects or
property sheet.