Allow subject field to support double byte characters (subject looks like =?utf-8?)

Hello,
I have been using this module for a while. I had a problem with sending double byte characters such as chinese using UTF-8 encoding.
The subject becomes unreadable strings like this
"=?utf-8?B?5Lit5paH5ris6Kmm5LqU5YWt5LiD5YWr5Lmd5Y2B5LiA55u05L6G5ris6Kmm"
when the subject has strings has a lot double byte characters, (more than 12 or 14 i think).

I have found out that the problem is because of phpmailer itself.
After searching on the web, I have found a solution to solve this problem.

Change line 920 of class.phpmailer.php

$result .= $this->HeaderLine('Subject', $this->EncodeHeader($this->SecureHeader($this->Subject)));

To

$result .= $this->HeaderLine('Subject', $this->EncodeHeader($this->SecureHeader($this->Subject),'text', 1));

And change line 1299 of class.phpmailer.php

public function EncodeHeader ($str, $position = 'text') { 

To

public function EncodeHeader ($str, $position = 'text', $pl = 0) {
if ( $pl ) return "=?" . $this->CharSet . "?B?" . base64_encode($str) . "?=";

And then change line 51 $CharSet = 'UTF-8';
And line 64 $Encoding = 'base64';

So far the subject displays the double byte characters without problem.

Hope this helps.

Leon