Fiber based std.process

[WebFreak001]

there should be a vibe alternative of std.process (especially spawnProcess and spawnShell) so one doesn't need to use worker tasks, handle exceptions, care about thread safety etc.

Spawning processes is often a very useful way to perform tasks and reuse programs that are difficult to implement if programming them into the code

[CyberShadow]

Some existing discussion:
http://forum.dlang.org/post/vjvmdacytocqbiodoqha@forum.dlang.org

One pertinent link posted there enumerating some of the challenges of this subject:
https://ldpreload.com/blog/signalfd-is-useless