Exiv2

Reported by Matthieu, original bugreport is http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=486884

Exif.Photo.UserComment unicode are stored a utf-16 (big or little
endianaccording to the exif endianness).

But exiv2 don't do any processing and output utf-16 on terminal [1].

Worse when setting UserComment with unicode charset, it write invalid
tag with the charset of your terminal.

PS : the perl exiftool does the encoding/decoding correctly.

[1] $wget http://castet.matthieu.free.fr/tmp/test_exif/IMG_0870_exiftool_usercomment_unicode.JPG
$exiv2 IMG_0870_exiftool_usercomment_unicode.JPG | grep "Exif comment" | hexdump -C
00000000 45 78 69 66 20 63 6f 6d 6d 65 6e 74 20 20 20 20 |Exif comment |
00000010 3a 20 00 75 00 6e 00 69 00 63 00 6f 00 64 00 65 |: .u.n.i.c.o.d.e|
00000020 00 20 00 74 00 65 00 73 00 74 00 20 00 3a 00 20 |. .t.e.s.t. .:. |
00000030 00 e9 00 e0 00 ea 0a |.