The exampes included in the repository have lagged behind the changes
made. Specifically, they do not use the new runtime construct.
This patch updates examples to use the latest features of Tokio.
Tokio is moving away from using `WouldBlock`, instead favoring
`Async::NotReady`.
This patch updates the TCP and UDP types, deprecating any function that
returns `WouldBlock` and adding a poll_ prefixed equivalent.
This commit removes the `Handle` argument from the following constructors
* `TcpListener::bind`
* `TcpStream::connect`
* `UdpSocket::bind`
The `Handle` argument remains on the various `*_std` constructors as they're
more low-level, but this otherwise is intended to set forth a precedent of by
default not taking `Handle` arguments and instead relying on the global
`Handle::default` return value when necesary.
This commit removes the `Reactor::run` method which has previously been used to
execute futures and turn the reactor at the same time. The tests/examples made
heavy usage of this method but they have now all temporarily moved to `wait()`
until the futures dependency is upgraded. In the meantime this'll allow us to
further trim down the `Reactor` APIs to their final state.
