[#88] Draft of foundations for `clone3()` syscall & friends

[michalfita]

This is draft for bringing in resolution for #88. The whole work is pretty complex, so probably would need to be split into pieces. I already defined a few things to fix first for get this any further.

I don't have much time to work on it, but I'll tray to add bits into it as time allows. Till then please look and comment.

Any input appreciated.

[nuta]

Fantastic! I'll check this tomorrow 😃