Full Threading Support

[stugol]

[Placeholder issue to ensure that threading support remains an active high-priority goal]

Crystal doesn't support threading. This is a mistake. Onyx needs to deviate from Crystal in that respect, for both performance reasons and to solve concurrency issues that stem from [a] fibers being sub-optimal in some cases and [b] IO.select being horribly broken for use in fibers.

[ozra]

Agreed.

By the time the core of Onyx is implemented and stabilized, it might very well have landed in Crystal, but if not, it will be a high-prio issue for me to take on, since I need it myself. And if deviation is necessary (PR's not accepted in Crystal repo) then that's the only way it can go.

I leave the high-pri tag off for now, since the core is the top-pri until done.

[ozra]

I took the liberty to edit out "HIGH PRIORITY: " from title - prioritization is in Roadmap issue.