0.7.1

- Drop support for Gtk2
- Drop Gtk3 ifdefs
- Switch to xfce_gtk_image_menu_item
- Add support for GObject Introspection (Fixes #4)
- Improve GObject introspection annotations (Fixes #8)
- Fix missing transfer annotation
- Field codes expansion API update
- Transfer some code to libxfce4util
- Fix default merge rules in xfce-applications.menu (Bug #15504)
- Rename exo-helpers to the new xfce4-xx ones
- Do not add INSTALL in dist tarball
- Fix a memory leak
- Switch to README.md and foreign automake mode
- README: Use table for debug arguments
- Add basic GitLab pipeline
- Translation Updates:
  Albanian, Asturian, Chinese (Hong Kong), Danish, Dutch, Eastern
  Armenian, Estonian, Greek, Hebrew, Indonesian, Interlingue, Norwegian
  Nynorsk, Polish, Portuguese, Uzbek, Uzbek (Latin)