Update comment on UTF-8/unicode.
Update comment on UTF-8/unicode.

BitFunnel/BitFunnel,danluu/BitFunnel,BitFunnel/BitFunnel,BitFunnel/BitFunnel,danluu/BitFunnel,BitFunnel/BitFunnel,BitFunnel/BitFunnel,BitFunnel/BitFunnel,danluu/BitFunnel,danluu/BitFunnel,danluu/BitFunnel,danluu/BitFunnel