New port for a linux executable

[vakarelov]

I needed an Linux executable for LZString for the server-side. The php port is just too slow. I created of fork of https://github.com/amiart/qt-lzstring and convert it to an app.
It can be found here: https://github.com/vakarelov/qt-lzstring

[Ryc O'Chet]

Do feel free to submit a PR to update the readme and point at it :-)