Release v0.8.2

Release v0.8.1

Release version 0.8.0

Breaking changes:

* Return `FromAsciiError` instead of the input when `AsciiString::from_ascii()` or `into_ascii_string()` fails.
* Replace the `no_std` feature with the additive `std` feature, which is part of the default features. (Issue tomprogrammer#29)
* `AsciiChar::is_*()` and `::as_{byte,char}()` take `self` by value instead of by reference.

Additions:

* Make `AsciiChar` comparable with `char` and `u8`.
* Add `AsciiChar::as_printable_char()` and the free functions `caret_encode()` and `caret_decode()`.
* Implement some methods from `AsciiExt` and `Error` (which are not in libcore) directly in `core` mode:
  * `Ascii{Char,Str}::eq_ignore_ascii_case()`
  * `AsciiChar::to_ascii_{upper,lower}case()`
  * `AsciiStr::make_ascii_{upper,lower}case()`
  * `{ToAsciiChar,AsAsciiStr}Error::description()`

Release v0.7.1

* Rename `Ascii` to `AsciiChar` and convert it into an enum. (with a …

…variant for every ASCII character)

* Replace `OwnedAsciiCast` with `IntoAsciiString`.
* Replace `AsciiCast` with `As[Mut]AsciiStr` and `IntoAsciiChar`.
* Add *from[_ascii]_unchecked* methods.
* Replace *from_bytes* with *from_ascii* in method names.
* Return `std::error::Error`-implementing types on error instead of `Option::None` or `Err(())`.
* Implement `AsciiExt` without the `unstable` Cargo feature flag, which is removed.
* Require Rust 1.9 or later.
* Add `#[no_std]` support in a Cargo feature.
* Implement `From<{&,&mut,Box<}AsciiStr>` for `[Ascii]`, `[u8]` and `str`
* Implement `From<{&,&mut,Box<}[Ascii]>`, `As{Ref,Mut}<[Ascii]>` and Default for `AsciiStr`
* Implement `From<Vec<Ascii>>` for `AsciiString`.
* Implement `AsMut<AsciiStr>` for `AsciiString`.
* Stop some `Ascii::is_xxx()` methods from panicking.
* Add `Ascii::is_whitespace()`.
* Add `AsciiString::as_mut_slice()`.
* Add raw pointer methods on `AsciiString`:
  * `from_raw_parts`
  * `as_ptr`
  * `as_mut_ptr`

v0.6.0: New features

There are more functions available:

- `Ascii` can be constructed from `u8`.
- `AsciiStr`s can be trimmed using `trim()`, `trim_left()` or
  `trim_right`.

Fix: Correct version number

I accidentally got a typo in my email in version 0.5.3 (only released on
crates.io) and forgot to raise the version number in the corrected build.

v0.5.1: Many more traits implemented

v0.5.0: Ascii builds on beta!

Please use the `unstable` cargo feature to enable additional
functionality.

If you used the traits `AsciiExt` or `OwnedAsciiExt` before this update
is a breaking change for you. Migration is as simple as enabling the
`unstable` cargo feature in the build.

[breaking-change]

v0.4.1: Follow changes in rustc