Replace hyper-0.10 with reqwest

Later versions of hyper (0.11, 0.12) have dropped a number of features,
and reqwest has picked up those features. This change migrates the HTTP
code from using an old version of hyper to using the latest version of
reqwest.

Other changes:
* Remove old and unused hyper_seekable
* Add UnexpectedHttpResponse

Cargo.toml

@@ -44,12 +44,11 @@ clap = "^2.29"
 error-chain = "^0.12"
 flate2 = "^1.0"
 fs2 = "^0.4"
-hyper = "^0.10"
-hyper-native-tls = "^0.3"
 lazy_static = "^1.2"
 libc = "^0.2"
 tempfile = "^3.0"
 md-5 = "^0.8"
+reqwest = "^0.9"
 sha2 = "^0.8"
 serde = { version = "^1.0", features = ["derive"], optional = true }
 tectonic_xdv = { path = "xdv", version = "0.1.9-dev" }

src/config.rs

@@ -149,7 +149,7 @@ impl PersistentConfig {
         only_cached: bool,
         status: &mut StatusBackend,
     ) -> Result<Box<Bundle>> {
-        use hyper::Url;
+        use reqwest::Url;
         use std::io;
 
         if CONFIG_TEST_MODE_ACTIVATED.load(Ordering::SeqCst) {

src/errors.rs

@@ -11,7 +11,7 @@
 #![allow(deprecated)]
 
 use app_dirs;
-use hyper;
+use reqwest::StatusCode;
 use std::io::Write;
 use std::result::Result as StdResult;
 use std::{convert, ffi, io, num, str};
@@ -27,11 +27,11 @@ error_chain! {
 
     foreign_links {
         AppDirs(app_dirs::AppDirsError);
-        Hyper(hyper::Error);
         Io(io::Error);
         Nul(ffi::NulError);
         ParseInt(num::ParseIntError);
         Persist(tempfile::PersistError);
+        Reqwest(reqwest::Error);
         TomlDe(toml::de::Error);
         TomlSer(toml::ser::Error);
         Utf8(str::Utf8Error);
@@ -64,6 +64,11 @@ error_chain! {
             description("some engine had an unrecoverable error")
             display("the {} engine had an unrecoverable error", engine)
         }
+
+        UnexpectedHttpResponse(url: String, status: StatusCode) {
+            description("unexpected HTTP response to URL")
+            display("unexpected HTTP response to URL {}: {}", url, status)
+        }
     }
 }