'Switch to the first window on next column'

def cmd_right(self):

    c = self.current_column()
    cidx = self.columns.index(c)
    if self.is_last_column(cidx):
        return
    cidx += 1
    c = self.columns[cidx]
    if (c['mode'] == 'split'):
        self.group.focus(c['rows'][0])
    else:
        self.group.focus(c['rows'][c['active']])
