[xslt] Isn't it time to make libxslt multi-threaded? (reborn)

[Дмитрий Грибов <grib gribuser ru>]

So, after two unsuccessful attempts to fix libxslt for faster & multithreaded work we have made our own xslt 
library.

Still in beta stage, some secondary features are missing by design, but mostly useful already.
Works ~10 (ten) times faster than LibXSLT for most of our tasks (not only because of multithreading).

One major thing left to do is to work with perl callbacks properly so that it would not conflict with 
multithreading architecture.

There also are some irrelevant for our case issues like encodings support and the like, but first things 
first: we need to improve our site performance.

Library:
https://github.com/Litres/turboxsl

Perl module:
https://github.com/Litres/TurboXSLT

Come aboard :)