Trivial changes in the Rust book.#27201

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bors merged 3 commits intorust-lang:masterfrom

Jul 22, 2015

Commits on Jul 21, 2015

Add info about usage of 'unsafe' keyword in bindings to foreign interfaces.
Ticki
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rust -> Rust
Ticki
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Klabnik nit-picks ;)
ticki
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