This patch renames `Sleep` from tokio-timer and the tokio facade to
`Delay`. Given that the future does not actually put anything to sleep,
the `Delay` name feels more appropriate.
Fixes#263
This patch adds a new crate: tokio-timer. This crate provides an
efficient timer implemeentation designed for use in Tokio based
applications.
The timer users a hierarchical hashed timer wheel algorithm with six
levels, each having 64 slots. This allows the timer to have a resolution
of 1ms while maintaining O(1) complexity for insert, removal, and firing
of timeouts.
There already exists a tokio-timer crate. This is a complete rewrite
which solves the outstanding problems with the existing tokio-timer
library.
Closes#146.
