This patch includes below tasks,
- Migrate to G_DECLARE_FINAL_TYPE
- Use g_autoptr
In the commit,
Migrate to G_DECLARE_FINAL_TYPE, the
G_DECLARE_FINAL_TYPE macro does not cover all of the five, or six manually defined macros in the previous version. However, I don't think all the previous macros are necessary and the macros
G_DECLARE_FINAL_TYPE provides are enough for freedesktop-dbus.