Log Message:
Update gtkdatabox to v1.0.0

From the changelog:

2021:
- Clean-up code for GTK3 and release it.
- Added new function to set the background color of databox:
  gtk_databox_set_bg_color().
- Added GtkDoc documentation option: ./configure --enable-gtk-doc.
- Removed libglade support, as it's not maintained anymore and
  depends on GTK2.