[xslt] XSLT 2.0

[Andriy Gerasika <andriy gerasika gmail com>]

Hello,
was experimenting w/ enhancing libxml2/libxslt to support XSLT 2.0:
https://github.com/andriy-gerasika/libxml2/commits/master

it is very lame, but I am not professional C/C++ developer, need some 
guidance:
a) support xpath2.0/xslt2.0 as a config option? (default no)
b) how to support unicode in lower-case() function --> use icu/iconv?

Andriy