Binary prefixes (such as Gi for ‘gibi-’ in GiB) are defined by
International Electrotechnical Commission (IEC) and not in the
International System of Units (SI).

So I just encountered this error for the first time. It's unclear what
it means, why I encountered it, or how to fix it. But worst of all, it
has a random newline and weird indentation! This commit fixes that last
bit.

Fix variable name typo

book: binary prefixed are defined by IEC and not in SI

Binary prefixes (such as Gi for ‘gibi-’ in GiB) are defined by
International Electrotechnical Commission (IEC) and not in the
International System of Units (SI).

Though to be honest I’d just reword the previous paragraph to use ‘1 GiB’.

enable tools to use test runners programmatically

Add Documentation for Custom Attributes and Error Reporting in Procedural Macros

This fixes rust-lang#39821 .

I'm not sure if the process of how to access custom attributes should be documented as well.
But I feel, that this should rather be documented in `syn`

Additional docs for Vec, String, and slice trait impls

r? @steveklabnik

Fix indentation of error message

So I just encountered this error for the first time. It's unclear what
it means, why I encountered it, or how to fix it. But worst of all, it
has a random newline and weird indentation! This commit fixes that last
bit.

<img width="680" alt="screen shot 2017-02-18 at 4 35 36 pm" src="https://cloud.githubusercontent.com/assets/1529387/23097087/0ef5ac4a-f5f9-11e6-9132-18ce759f7092.png">

…sxcv

Add missing urls and examples into Barrier structs

r? @frewsxcv

Clarify thread::Builder::stack_size docs

Add two pieces of information:

* the size is in bytes
* the actual stack size might be bigger.

Also change the example to use a more realistic value of 32 kilobytes.

r? @steveklabnik

…crichton

Update std::fmt module docs for landing of rust-lang#33642.

Since rust-lang#33642, it's no longer true that all references to a given format argument must use the same type. The docs don't seem to have been updated.

Update exception-safety.md

Fix variable name typo

Add missing urls in MutexGuard docs

r? @frewsxcv

…s, r=GuillaumeGomez

Correct another typo in procedural macros chapter of the Book.

Another (and the only remaining) instance of the lets/let's mistake fixed in c8292fc / 36b00cf.

r? @steveklabnik