Add loot disk "parallel"

The code works, its ok to call it beta.
I created man entries only for few functions, please review if I have started it correctly.
Comments on code, style, bugs and features are welcome.
I have no idea what does this may/should do, but I bet that it is meant to tell the system that it is call from.. system. And putting thing like that into OpenOS is bad. You should override coroutine in user envirnoment(note that this doesn't mean _G). the custom yield should somehow tell that the yield was caused by user. IIRC that kind of stuff was done in OC kernel.lua