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(Only the first 15 lines of the commit message are shown above )