Fixed some compiler warnings and added extra check to glade_widget_set_object() to make sure there is an adaptor.
Fixed bug 702886 "SEGV when creating a new GtkDialog (GLib 2.37.x)"
glib changed the order construct properties are set which exposed this bug,
now they are set in the order they are installed in the class.
So we fixed the bug by installing adaptor property first and object last.