Add the extra charset decoders from SquirrelMail.
This package contains extra decoding functions.
SquirrelMail decoding functions are used to display and convert messages
encoded in different character sets. Extra decoding library provides support
of some complex Eastern character sets and some rarely used Apple character
sets. Current release supports Big5, Windows-874 (cp874, Thai), Windows-949
(UHC, Korean), EUC-CN, EUC-JP, EUC-KR, EUC-TW, GB18030, GB2312, ISO-2022-CN,
ISO-2022-JP, ISO-2022-JP-2, ISO-2022-KR, Shift_JIS and various x-mac-*
Extra decoding library can be used in SquirrelMail 1.4.4 or newer. It depends
on sq_is8bit() function. In order to optimize decoding of Eastern character
sets, PHP installation needs recode (http://www.php.net/recode) or iconv
(http://www.php.net/iconv) support. Some decoding functions can use mbstring
functions present in php 4.3.0. Mbstring decoding needs sq_mb_list_encodings()
function from SquirrelMail 1.5.1 or 1.4.6.
Some decoding code that be activated only when $aggressive_decoding variable
is set to true. This variable should be enabled only on smaller systems, that
don't call aggressive decoding functions very often. Turning on
$aggressive_decoding variable by default in packaged SquirrelMail versions is
Feature safe: yes