[HarfBuzz] Guessing the script of a string.

[Eduardo Castiñeyra]

Hi,

I have been reviewing the hb_script_from_string code, and I don't 
understand how does it work. It seems like it were expecting some kind 
of 4-letter code at the begining of the string.

Wouldn't it be more usefull to guess the script based on the Unicode 
ranges the chars are in based on the http://www.unicode.org/charts table?

Regards!