def column_hidden colindex, tf=true
      #raise ArgumentError, "wrong alignment value sent" if ![:right, :left, :center].include? lrc
      get_column(colindex).hidden = tf
      @repaint_required = true
      @recalc_required = true
    end
def column_hidden colindex, tf=true
      #raise ArgumentError, "wrong alignment value sent" if ![:right, :left, :center].include? lrc
      get_column(colindex).hidden = tf
      @repaint_required = true
      @recalc_required = true
    end
Set a column to hidden  TODO we are not actually doing that