Update fannkuchredux benchmark

From the discussion on reddit:
http://www.reddit.com/r/rust/comments/2fenlg/benchmark_improvement_fannkuchredux/

This adds two variants: the primary, that uses an unsafe block, and a secondary
that is completely safe.

The one with the unsafe block matches clang's performance and beats gcc's.
Check concrete type in impls with no trait

closes #16955
Make integer bit count methods return uints

Fixes rust-lang/rfcs#224
rustdoc/html: emphasize the crate part of the full path.
Remove unused diagnostic codes.

Fixes #16449.
Fix formatting in the guide.

Thanks @dherman.
don't say compromise

@dherman doesn't like it :smile:
Optimize Slice::reverse

This makes the completely safe implementation of fannkuchredux perform
the same as C++. Yay, Rust.
Fix documentation typo.
auto merge of #17003 : nick29581/rust/impl, r=pcwalton

closes #16955 

r? @pcwalton
fix a sized deallocation issue in the glue code
fix sized deallocation for proc
auto merge of #17011 : nodakai/rust/rustdoc-stronger-crate, r=alexcrichton

If you browse to, say, http://doc.rust-lang.org/libc/types/os/common/posix01/struct.timeval.html , you will see the "location" window showing `libc::types::os::common::posix01`.  The first element points to a crate and others point modules.  This patch adds the bold attribute to the first (ie. crate) element so that it stands out more.
fix sized deallocation for Box<[T]>
fix sized deallocation for OwnedSlice
fix sized deallocation for TypedArena<T>
auto merge of #17012 : thestinger/rust/sized, r=nikomatsakis
auto merge of #16999 : brson/rust/fannkuch, r=alexcrichton

From the discussion on reddit:
http://www.reddit.com/r/rust/comments/2fenlg/benchmark_improvement_fannkuchredux/

This adds two variants: the primary, that uses an unsafe block, and a secondary
that is completely safe.

The one with the unsafe block matches clang's performance and beats gcc's.
auto merge of #17016 : steveklabnik/rust/fix_diagnostic_codes, r=huonw

Fixes #16449.
auto merge of #17018 : steveklabnik/rust/fix_projects_in_guide, r=huonw

Thanks @dherman.