Implement thread-local Waker

[Thomasdezeeuw]

Also for use of less expensive operations.

[Thomasdezeeuw]

Also see rust-lang/rfcs#2418 (comment).

[Thomasdezeeuw]

Also see #40.

[Thomasdezeeuw]

The waker trait is being redesigned, see rust-lang/rfcs#2592. After that makes into the standard library I'll start work on this.

Current idea:

Two waker implementations. LocalWaker will be backed by Mio-st simply adding user space notifications, via an ActorsystemRef. The Waker (thread-safe) implementation will likely use a channel to send ProcessId to other ActorSystems, this still means #49 needs to be fixed.

Other notes:

• Try to remove Waker from ActorProcess. Create a new LocalWaker each time from ActorSystemRef and ProcessId?

[Thomasdezeeuw]

Pr to change Waker implementation: rust-lang/rust#57992.

[Thomasdezeeuw]

Pr with new Waker implementation is merged, now blocked on updating Rust version, see #163.

[Thomasdezeeuw]

LocalWaker is no longer a thing and after #215 the Waker is fairly decent shape, closing this.