docs(changelog): improve breaking changes list with more details

CHANGELOG.md

@@ -1,18 +1,15 @@
 ## v0.12.0 (2018-06-01)
 
-
-#### Bug Fixes
-
-* **lib:** remove deprecated tokio-proto APIs ([a37e6b59](https://github.com/hyperium/hyper/commit/a37e6b59e6d6936ee31c6d52939869933c709c78))
-* **server:** panic on max_buf_size too small ([aac250f2](https://github.com/hyperium/hyper/commit/aac250f29d3b05d8c07681a407825811ec6a0b56))
-
-
 #### Features
 
+* **lib:**
+  * add HTTP/2 support for Client and Server ([c119097f](https://github.com/hyperium/hyper/commit/c119097fd072db51751b100fa186b6f64785954d))
+  * convert to use tokio 0.1 ([27b8db3a](https://github.com/hyperium/hyper/commit/27b8db3af8852ba8280a2868f703d3230a1db85e))
+  * replace types with those from `http` crate ([3cd48b45](https://github.com/hyperium/hyper/commit/3cd48b45fb622fb9e69ba773e7f92b9d3e9ac018))
 * **body:**
   * remove `Body::is_empty()` ([19f90242](https://github.com/hyperium/hyper/commit/19f90242f8a3768b2d8d4bff4044a2d6c77d40aa))
   * change `Payload::Data` to be a `Buf` ([a3be110a](https://github.com/hyperium/hyper/commit/a3be110a55571a1ee9a31b2335d7aec27c04e96a), closes [#1508](https://github.com/hyperium/hyper/issues/1508))
-  * add From<Box<Stream>> impl for Body ([45efba27](https://github.com/hyperium/hyper/commit/45efba27df90650bf4669738102ad6e432ddc75d))
+  * add `From<Box<Stream>>` impl for `Body` ([45efba27](https://github.com/hyperium/hyper/commit/45efba27df90650bf4669738102ad6e432ddc75d))
   * introduce a `Payload` trait to represent bodies ([fbc449e4](https://github.com/hyperium/hyper/commit/fbc449e49cc4a4f8319647dccfb288d3d83df2bd), closes [#1438](https://github.com/hyperium/hyper/issues/1438))
 * **client:**
   * rename `FutureResponse` to `ResponseFuture` ([04c74ef5](https://github.com/hyperium/hyper/commit/04c74ef596eb313b785ecad6c42c0375ddbb1e96))
@@ -22,16 +19,16 @@
   * improve construction of `Client`s ([fe1578ac](https://github.com/hyperium/hyper/commit/fe1578acf628844d7cccb3e896c5e0bb2a0be729))
   * redesign the `Connect` trait ([8c52c2df](https://github.com/hyperium/hyper/commit/8c52c2dfd342e798420a0b83cde7d54f3af5e351), closes [#1428](https://github.com/hyperium/hyper/issues/1428))
 * **error:** revamp `hyper::Error` type ([5d3c4722](https://github.com/hyperium/hyper/commit/5d3c472228d40b57e47ea26004b3710cfdd451f3), closes [#1128](https://github.com/hyperium/hyper/issues/1128), [#1130](https://github.com/hyperium/hyper/issues/1130), [#1431](https://github.com/hyperium/hyper/issues/1431), [#1338](https://github.com/hyperium/hyper/issues/1338))
-* **http2:** add HTTP/2 support for Client and Server ([c119097f](https://github.com/hyperium/hyper/commit/c119097fd072db51751b100fa186b6f64785954d))
-* **lib:**
-  * convert to use tokio 0.1 ([27b8db3a](https://github.com/hyperium/hyper/commit/27b8db3af8852ba8280a2868f703d3230a1db85e))
-  * replace types with those from http crate ([3cd48b45](https://github.com/hyperium/hyper/commit/3cd48b45fb622fb9e69ba773e7f92b9d3e9ac018))
 * **rt:** make tokio runtime optional ([d127201e](https://github.com/hyperium/hyper/commit/d127201ef22b10ab1d84b3f2215863eb2d03bfcb))
 * **server:**
   * support HTTP1 and HTTP2 automatically ([bc6af88a](https://github.com/hyperium/hyper/commit/bc6af88a32e29e5a4f3719d8abc664f9ab10dddd), closes [#1486](https://github.com/hyperium/hyper/issues/1486))
   * re-design `Server` as higher-level API ([c4974500](https://github.com/hyperium/hyper/commit/c4974500abee45b95b0b54109cad15978ef8ced9), closes [#1322](https://github.com/hyperium/hyper/issues/1322), [#1263](https://github.com/hyperium/hyper/issues/1263))
 * **service:** introduce hyper-specific `Service` ([2dc6202f](https://github.com/hyperium/hyper/commit/2dc6202fe7294fa74cf1ba58a45e48b8a927934f), closes [#1461](https://github.com/hyperium/hyper/issues/1461))
 
+#### Bug Fixes
+
+* **lib:** remove deprecated tokio-proto APIs ([a37e6b59](https://github.com/hyperium/hyper/commit/a37e6b59e6d6936ee31c6d52939869933c709c78))
+* **server:** panic on max_buf_size too small ([aac250f2](https://github.com/hyperium/hyper/commit/aac250f29d3b05d8c07681a407825811ec6a0b56))
 
 #### Breaking Changes
 
@@ -78,8 +75,7 @@
   to construct. Code will need to be updated accordingly.
 
   For body streams or `Service`s, inference might be unable to determine
-  what error type you mean to return. Starting in Rust 1.26, you could
+  what error type you mean to return.
-  just label that as `!` if you never return an error.
 
   ([5d3c4722](https://github.com/hyperium/hyper/commit/5d3c472228d40b57e47ea26004b3710cfdd451f3))
 * All uses of `Handle` now need to be new-tokio `Handle`.
@@ -97,7 +93,7 @@
   `Connected::new()`.
 
   ([8c52c2df](https://github.com/hyperium/hyper/commit/8c52c2dfd342e798420a0b83cde7d54f3af5e351))
-* All code that was assuming the body was a `Stream` must
+* All code that was generic over the body as `Stream` must
   be adjusted to use a `Payload` instead.
 
   `hyper::Body` can still be used as a `Stream`.
@@ -111,18 +107,51 @@
   ([fbc449e4](https://github.com/hyperium/hyper/commit/fbc449e49cc4a4f8319647dccfb288d3d83df2bd))
 * `Method`, `Request`, `Response`, `StatusCode`,
   `Version`, and `Uri` have been replaced with types from the `http`
-  crate. The `hyper::header` module is gone for now.
+  crate.
-
-  Removed `Client::get`, since it needed to construct a `Request<B>`
-  with an empty body. Just use `Client::request` instead.
-
-  Removed `compat` cargo feature, and `compat` related API.
 
   ([3cd48b45](https://github.com/hyperium/hyper/commit/3cd48b45fb622fb9e69ba773e7f92b9d3e9ac018))
-* Many of these APIs have been deprecated for a while,
+  * The variants of `Method` are now uppercase, for instance, `Method::Get` is now `Method::GET`.
-  check the documentation for the recommended way to use hyper now.
+  * The variants of `StatusCode` are now uppercase, for instance, `StatusCode::Ok` is now `StatusCode::OK`.
+  * The variants of `Version` are now uppercase, for instance, `HttpVersion::Http11` is now `Version::HTTP_11`.
+*  The typed headers from `hyper::header` are gone for now.
   
+  The `http::header` module is re-exported as `hyper::header`.
+  
+  For example, a before setting the content-length:
+  
+  ```rust
+  use hyper::header::ContentLength;
+  res.headers_mut().set(ContentLength(15));
+  ```
+  
+  And now **after**, with the `http` types:
+  
+  ```rust
+  use hyper::header::{CONTENT_LENGTH, HeaderValue};
+  res.headers_mut().insert(CONTENT_LENGTH, HeaderValue::from_static("15"));
+  ```
+  
+  ([3cd48b45](https://github.com/hyperium/hyper/commit/3cd48b45fb622fb9e69ba773e7f92b9d3e9ac018))
+* The `mime` crate is no longer re-exported as `hyper::mime`.
+
+  The typed headers don't exist, and so they do not need the `mime` crate.
+
+  To continue using `mime` for other purposes, add it directly to your `Cargo.toml`
+  as a dependency.
+
+  ([3cd48b45](https://github.com/hyperium/hyper/commit/3cd48b45fb622fb9e69ba773e7f92b9d3e9ac018))
+* Removed `compat` cargo feature, and `compat` related API. This was the conversion methods for hyper's
+  types to and from `http` crate's types.
+
+  ([3cd48b45](https://github.com/hyperium/hyper/commit/3cd48b45fb622fb9e69ba773e7f92b9d3e9ac018))
+* Removed deprecated APIs:
   ([a37e6b59](https://github.com/hyperium/hyper/commit/a37e6b59e6d6936ee31c6d52939869933c709c78))
+  * The `server-proto` cargo feature, which included `impl ServerProto for Http`, and related associated types.
+  * `client::Config::no_proto()`
+  * `tokio_proto::streaming::Body::from(hyper::Body)`
+  * `hyper::Body::from(tokio_proto::streaming::Body)`
+  * `hyper::Body::from(futures::sync::mpsc::Receiver)`
+  * `Http::no_proto()`
 
 
 ### v0.11.27 (2018-05-16)