Fix more rustdoc links (#518)

* Fix a cut-paste error with -reactor rustdoc links
* Fix more ::reactor rustdoc broken links
* Minor rustdoc typo
* Consistently reference std::io::{Read, Write} in rustdoc/links

src/executor/mod.rs

@@ -13,7 +13,7 @@
 //!
 //! The specific strategy used to manage the tasks is left up to the
 //! executor. There are two main flavors of executors: single-threaded and
-//! multithreaded. Tokio provides implementation for both of these in the
+//! multi-threaded. Tokio provides implementation for both of these in the
 //! [`runtime`] module.
 //!
 //! # `Executor` trait.

src/reactor/mod.rs

@@ -132,8 +132,8 @@
 //! [`Poll::poll`]: https://docs.rs/mio/0.6/mio/struct.Poll.html#method.poll
 //! [`mio::Evented`]: https://docs.rs/mio/0.6/mio/trait.Evented.html
 //! [`PollEvented`]: struct.PollEvented.html
-//! [`std::Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
-//! [`std::Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
+//! [`std::io::Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
+//! [`std::io::Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
 
 pub use tokio_reactor::{
     Reactor,