Replace reqwest with hyper (#8099)

* Very primitive test of the Client API

* [WIP] getting rid of request

* Add support for redirects.

* Remove CpuPool from `fetch::Client`.

* Adapt code to API changes and fix tests.

* Use reference counter to stop background thread.

On `clone` the counter is incremented, on `drop` decremented. Once 0 we
send `None` over the channel, expecting the background thread to end.

* Fix tests.

* Comment.

* Change expect messages.

* Use local test server for testing fetch client.

* Ensure max_size also in BodyReader.

* Replace `Condvar` with `sync_channel`.

* Re-export `url::Url` from `fetch` crate.

* Remove spaces.

* Use random ports in local test server.

dapps/src/apps/fetcher/installers.rs

@@ -19,9 +19,10 @@ use std::{fs, fmt};
 use std::io::{self, Read, Write};
 use std::path::PathBuf;
 use ethereum_types::H256;
-use fetch::{self, Mime};
+use fetch;
 use futures_cpupool::CpuPool;
 use hash::keccak_buffer;
+use mime_guess::Mime;
 
 use apps::manifest::{MANIFEST_FILENAME, deserialize_manifest, serialize_manifest, Manifest};
 use handlers::{ContentValidator, ValidatorResponse};
@@ -53,7 +54,7 @@ fn write_response_and_check_hash(
 
 	// Now write the response
 	let mut file = io::BufWriter::new(fs::File::create(&content_path)?);
-	let mut reader = io::BufReader::new(response);
+	let mut reader = io::BufReader::new(fetch::BodyReader::new(response));
 	io::copy(&mut reader, &mut file)?;
 	file.flush()?;