Refactored build-binary-snapshots script. More in details.
Refactored build-binary-snapshots script. More in details.

* Use multithreaded xz with threads by default equal to amount of CPU cores
* Really clean unwanted dirs from jails base before creating snapshot.
* fix: Avoid any user interaction requirements
* DRY the world

VerKnowSys/ServeD-OS,VerKnowSys/ServeD-OS,VerKnowSys/svdOS,VerKnowSys/svdOS,VerKnowSys/svdOS