Create a new PangoScriptIter, used to break a string of
Unicode into runs by text. No copy is made of text,
Usage
pangoScriptIterNew(text, length)
Arguments
text
[char] a UTF-8 string
length
[integer] length of text, or -1 if text is nul-terminated.
Value
PangoScriptIter] the new script iterator, initialized
to point at the first range in the text, If the string is
empty, it will point at an empty range.