#1621 Add support for xz compression

[Michal Čihař]

The xz compression works way better than bzip2 and gzip, so it would be great if phpMyAdmin supports it for both compressing SQL dumps and for decompressing them.

The problem is that there is currently no native support in PHP, only third party module:

https://github.com/payden/php-xz

[Isaac Bennetch]

Personally, I think it's not worth implementing yet. If/when it becomes a native PHP function, then I'd agree, but for now I don't see much need.

That being said, it doesn't look like we'd experience much overhead or extra work to include support for this, so I also don't object to it.

[Madhura Jayaratne]

Some initial work on this https://github.com/phpmyadmin/phpmyadmin/pull/1628