Clean ISO-8859-1 embedded in mail subjects or filenames

See 6x issue: http://drupal.org/node/1029134

User Agents, such as Thunderbird, Apple Mail or iOS Mail, encodes both subject and filenames using ISO-8859-1, UTF8 or other if a special caracter is present in it.
For example, a mail with subject "Fwd : boite à lettres' appears as : Fwd: boites =?ISO-8859-1?Q?=E0_lettres?= ... Ugly.

Here is my fix for 7.x

In mailhandler/plugins/commands_plugin/MailhandlerCommandsFiles.class.php in line 20, replace:

$filename = $attachment->filename;

with

$filename = mb_decode_mimeheader($attachment->filename);

In mailhandler/plugins/commands_plugin/MailhandlerCommandsHeaders.class.php in line 18, replace:

$message[$key] = $value;

with

			if ( in_array($key, array('Subject', 'subject') )) {
				$message[$key] = iconv_mime_decode($value,0,"UTF-8");	
			}	
			else
			{
				$message[$key] = $value;
			} 

I used iconv_mime_decode(); because imap_utf8(); translatet everything in to UPPERCASE. This is a known bug: https://bugs.php.net/bug.php?id=44098