tr is not working correctly with Turkish locale

[Ismail Donmez]

Hi,

All tr versions up to including coreutils 5.3.0 seems to be buggy with Turkish 
locale :

address@hidden ~ $ echo $LANG
tr_TR.UTF-8

# problematic with i-dotless
address@hidden ~ $  echo "IĞÜŞİÖÇ" | tr 'IĞÜŞİÖÇ' 'ığüşiöç' 
ğ�üşiöç

# completely broken
address@hidden ~ $  echo "IĞÜŞİÖÇ" | tr '[:upper:]' '[:lower:]' 
IĞÜŞİÖÇ

Expected output is this:

address@hidden ~ $  echo "IĞÜŞİÖÇ" | tr 'IĞÜŞİÖÇ' 'ığüşiöç'
ığüşiöç
address@hidden ~ $  echo "IĞÜŞİÖÇ" | tr '[:upper:]' '[:lower:]'
ığüşiöç