test: 'ratcher' is not a word
std: mark two helper functions #[inline].

`str::utf8_char_width` and `char::from_u32` are tiny, which means it's a
big performance hit to call them in a tight loop outside libstd.
std: Remove some nonsense from old std::io docs

Most of this stuff is irrelevant implementation notes from last year.
This trims out the stuff that isn't appropriate for user-facing docs.
Fix C function FFI example in the Rust cheatsheet
Tutorial: fix typo
Merge remote-tracking branch 'kud1ing/patch-1'
Merge remote-tracking branch 'tbu/pr_doc_smallfix'
Merge remote-tracking branch 'brson/iodoc'
Merge remote-tracking branch 'brson/ratcher'
Merge remote-tracking branch 'huonw/inline-helpers'
auto merge of #12509 : brson/rust/rollup, r=brson

Rollup of https://github.com/mozilla/rust/pull/12506, https://github.com/mozilla/rust/pull/12500, https://github.com/mozilla/rust/pull/12480, https://github.com/mozilla/rust/pull/12478, https://github.com/mozilla/rust/pull/12461.
Update rustc/syntax docs now that rustdoc lexes all non-`notrust` code blocks.

This includes blocks made by indentation, so they need to be changed to
explicitly have ```notrust ... ``` fences..
auto merge of #12510 : huonw/rust/fix-compiler-docs, r=alexcrichton

This includes blocks made by indentation, so they need to be changed to
explicitly have ```notrust ... ``` fences..
Remove all ToStr impls, add Show impls

This commit changes the ToStr trait to:

    impl<T: fmt::Show> ToStr for T {
        fn to_str(&self) -> ~str { format!("{}", *self) }
    }

The ToStr trait has been on the chopping block for quite awhile now, and this is
the final nail in its coffin. The trait and the corresponding method are not
being removed as part of this commit, but rather any implementations of the
`ToStr` trait are being forbidden because of the generic impl. The new way to
get the `to_str()` method to work is to implement `fmt::Show`.

Formatting into a `&mut Writer` (as `format!` does) is much more efficient than
`ToStr` when building up large strings. The `ToStr` trait forces many
intermediate allocations to be made while the `fmt::Show` trait allows
incremental buildup in the same heap allocated buffer. Additionally, the
`fmt::Show` trait is much more extensible in terms of interoperation with other
`Writer` instances and in more situations. By design the `ToStr` trait requires
at least one allocation whereas the `fmt::Show` trait does not require any
allocations.

Closes #8242
Closes #9806
Remove deriving(ToStr)

This has been superseded by deriving(Show).

cc #9806