Upgrading hyper 0.10 to 0.11

Removes deprecated StatusClass.

The Cookie header is no longer a wrapper over a Vec<String> and must be accessed via its get and set methods.

HttpDate no longer has public fields; convert between HttpDate and SystemTime as needed.

Removes the link_extensions methods of the Link header until fixed.

Removes several deprecated methods for converting Headers into strings; use more specialized methods instead.

The Url type is no longer used; Client API instances use hyper::Uri, Error::Uri becomes hyper::error::UriError, and HTTP_VALUE is private.

Renames Preference::HandlingLeniant to Preference::HandlingLenient to fix a typo in the variant and its string representation.

Server is no longer the primary entry point; an Http type is created and then bound to receive a Server or passed to other Tokio things.

The fields of the Host header are no longer available; use the getter methods instead.

Headers.remove() now returns Option<H> instead of bool; use Headers.has() to check if a header exists.

Removes the mime! macro, Mime constructor, and TopLevel and SubLevel enums; use constants or parse a string instead.

Response.status() now returns a StatusCode by value.

Redesigns the API to use Futures and Tokio.

Switches to non-blocking (asynchronous) IO.

Redesigns the RequestUri type into Uri, an opaque struct with getter methods instead of an enum.

Any use of Quality(num) should change to q(num).

The fmt_header method now takes a different formatter; headers implementing fmt::Display can call f.fmt_line(self).

The Encoding enum gains an additional variant, Trailers.

Origin.scheme and Origin.host now return Options, since Origin could be null.

Explicit StatusCode checks such as equality comparisons must use the value instead of a reference.

Request.remote_addr is now an Option<SocketAddr> instead of SocketAddr.

Adds a new variant to the Encoding enum, which can break exhaustive matches.

A big sweeping set of breaking changes.

Header::parse_header now receives &Raw instead of &[Vec<u8>], requiring changes to existing implementations.

LanguageTag moves from the crate root to the hyper::header module.

Removes undocumented from_u16 and makes the status module private; use StatusCode::try_from and hyper::StatusCode.

Replaces status.class() usage with the equivalent status.is_*() methods.

Using RawStatus now requires enabling the raw_status crate feature.

Some headers now use unicase::Ascii instead of UniCase; upgrade code to Ascii::new(s).

Breaks many Client and Server APIs; Handlers are now used for asynchronous events per the documentation.

Removes logs that contain request and response data.