void gtk_label_set_justify ( GtkLabel* self, GtkJustification jtype )
Sets the alignment of the lines in the text of the label relative to each other.
GTK_JUSTIFY_LEFT is the default value when the widget is first created
gtk_label_new(). If you instead want to set the alignment of
the label as a whole, use
gtk_label_set_justify() has no effect on labels containing
only a single line.