This makes the tests much less brittle, by not depending on the exact
order of the HTTP headers, nor always requiring to check for every
single header.
- The `Error`'s kind is a now a set of variants depending on the context
of when an error could occur.
- If another error was the cause, it is now always the `source`.
Along with the `is_*` methods, this should help in understanding *when*
a certain error occurred. For example, an error setting the TLS
certificates will return a builder error, with the TLS error as the
source. This should help differentiate from a TLS error that happens
when connecting to a server.
It also makes the internal code less dependent on all the exact
dependencies that can be enabled or disabled.
"inflate" actually means decompress in the context of DEFLATE. "deflate" reduces the size of something, i.e. compression, and inflate is the opposite, i.e. decompression.
- Converted `Response::text` and `Response::json` to `async fn`
- Added `Response::bytes` async fn as a counterpat to `text`.
- Added `Response::chunk` async fn to stream chunks of the response body.
- Added `From<Response> for Body` to allow piping a response as a request body.
- Removed `Decoder` from public API
- Removed body accessor methods from `Response`
- Removed `Chunk` type, replaced with `bytes::Bytes`.
- Removed public `impl Stream for Body`.
Before the fix anything other than 200 & 407 would throw an unhelpful
`unsuccessful tunnel` error.
After this change,
- Explicit handling of 403, where the proxy forbids a connection.
- All other responses will be part of the error message.
