compare lower case and upper case when encoding is utf-8

Hi hackers,

I found that lower case is less than upper case when the db is created
with utf8.
I tried below
locale en_US.utf8 'A'<'a' false
locale ja_JP.utf8 'A'<'a' true
locale zh_CN.utf8 'A'<'a' false
Under Windows
locale Chinese_China 'A'<'a' false

I am not sure it is normal or not.
But in Chinese, the lower case should be greater than upper, same as
locale C.

I made some code try to fix it.
It seems to work fine.

Quan Zongliang