Highlight inline changes in both lines.

def _highlight_line_udiff(self, line, next):
        """
        Highlight inline changes in both lines.
        """
        start = 0
        limit = min(len(line['line']), len(next['line']))
        while start < limit and line['line'][start] == next['line'][start]:
            start += 1
        end = -1
        limit -= start
        while -end <= limit and line['line'][end] == next['line'][end]:
            end -= 1
        end += 1
        if start or end:
            def do(l):
                last = end + len(l['line'])
                if l['action'] == 'add':
                    tag = 'ins'
                else:
                    tag = 'del'
                l['line'] = '%s<%s>%s</%s>%s' % (
                    l['line'][:start],
                    tag,
                    l['line'][start:last],
                    tag,
                    l['line'][last:]
                )
            do(line)
            do(next)