Fix overflow in rgb() parsing.

`some_f32 as i32` would warp

Auto merge of servo#140 - servo:unbound, r=nox

Remove broken support for bindings inside match_ignore_ascii_case.

Fix servo#126.

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Make function generated by ascii_case_insensitive_phf_map public.

procedural-masquerade v0.1.2

Auto merge of servo#121 - manuel-woelker:pr-color-level-4, r=emilio,S…

…imonSapin

color: Support CSS Color Level 4 rgb & hsl syntax (servo#113)

Fixes servo#113 - Feedback welcome!

If I interpret the spec correctly, in the whitespace-split version the alpha channel is separated with a `/`.
I also added support for angle values (deg/grad/rad/turn) in the hue position.

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Auto merge of servo#123 - servo:proc-macro-hack, r=nox

Rewrite procedural macro based on the enum discriminant trick

We can improve on this with an idea from @dtolnay:

```rust
enum Dummy {
    Input = (0, stringify!( ... )).0
}
```

Instead of a custom attribute, we use an enum with an explicit discriminant (because that’s the only case where a type definition can contain a (const) expression), together with accessing the first field of a literal tuple to ignore other fields.

Instead of just string literals, we can accept arbitrary tokens that `stringify!` will later be expanded into something parseable in a const expression context. (`stringify!` doesn’t help in attributes because it is not yet expanded by the time anything other than string literals is rejected.)

The details of this hack are hidden away into a new crate, called [`procedural-masquerade`](https://docs.rs/procedural-masquerade/).

----

This enables concrete benefits for users of cssparser:

* `match_ignore_ascii_case!` now supports the full syntax of `match` expressions, including alternatives `pattern | other_pattern`, bindings `name @ pattern`, and guards `pattern if condition`.
* Map values in `asci_case_insensitive_phf_map!` are now given literally instead of as string literals containing Rust syntax.

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English spelling

Merge pull request servo#122 from servo/macros

Make match_ignore_ascii_case more efficient, add ascii_case_insensitive_phf_map

Auto merge of servo#114 - nox:serde, r=Ms2ger

Update serde to 0.9.0

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