…ransmute.

In #[no_std] environments, std::mem::transmute is unavailable. Searching for transmute in libcore only pulls up core::intrinsics::transmute, which is behind the (unstable) core_intrinsics feature flag. Users wishing to use transmute in #[no_std] environments typically should use core::mem::transmute instead, as it is stable. This documentation makes core::mem::transmute discoverable.

…::mem::transmute, create documentation pages for them.

This renders them discoverable via search. I removed the mention of the exports in the transmute documentation, but can re-add it if desired.

…=QuietMisdreavus

Re-enable history api on file:// protocol

Fixes rust-lang#57135.

I tested locally on chrome (since it was the browser having issues with history management on `file://` protocol) and it worked fine so I guess we can re-enable it.

r? @QuietMisdreavus

…ietMisdreavus

Generate a documentation page for core::mem::transmute.

In `#[no_std]` environments, `std::mem::transmute` is unavailable. Searching for "core transmute" online only pulls up `core::intrinsics::transmute`, which is behind the (unstable) `core_intrinsics` feature flag. Users wishing to use transmute in `#[no_std]` environments typically should use `core::mem::transmute` instead, as it is stable. This documentation makes `core::mem::transmute` discoverable.

…y, r=QuietMisdreavus

Update minifier version

Should fix rust-lang#57754 (at least it's a bit faster on my computer).

The whole point of this update is to create a huge array instead of creating a lot of variables.

r? @QuietMisdreavus

…sdreavus

rustdoc: remove blank unstable spans

Rustdoc generates blank unstable spans for unstable struct fields: ![screen shot 2019-01-28 at 1 05 04 pm](https://user-images.githubusercontent.com/1372438/51856295-5e8ed500-22fd-11e9-8074-025eddb4ef65.png)

This PR removes them:
![screen shot 2019-01-28 at 1 07 22 pm](https://user-images.githubusercontent.com/1372438/51856424-aada1500-22fd-11e9-86f0-34e2aa78b8b1.png)

r? @QuietMisdreavus

…ink, r=QuietMisdreavus

Fix image link in the settings menu

Fixes rust-lang#57892.

r? @QuietMisdreavus

rustdoc: wrap stability tags in colored spans

A cosmetic change to make the stability tags stand out a bit against the docs. Opening for discussion.

Before:

![screen shot 2019-01-31 at 3 29 36 pm](https://user-images.githubusercontent.com/1372438/52083406-54730d80-256d-11e9-8e61-b8caff569434.png)
![screen shot 2019-01-31 at 3 31 32 pm](https://user-images.githubusercontent.com/1372438/52083408-54730d80-256d-11e9-97b7-43e808448f65.png)

After:
![screen shot 2019-01-31 at 3 29 18 pm](https://user-images.githubusercontent.com/1372438/52083405-54730d80-256d-11e9-9983-19d9519b2ed8.png)
![screen shot 2019-01-31 at 3 29 46 pm](https://user-images.githubusercontent.com/1372438/52083407-54730d80-256d-11e9-8c32-11a1ad7d3f34.png)

r? @QuietMisdreavus

…provement, r=Manishearth

[rustdoc] Improve file list display

Improve a bit the arrows to show a folder's file and the arrow to show/hide the left panel.

r? @QuietMisdreavus

…ebar, r=QuietMisdreavus

Sort elements in the sidebar

Fixes rust-lang#57448.

Not sorting fields or variants though.

r? @QuietMisdreavus

…hing, r=QuietMisdreavus

Prevent automatic collapse of methods impl blocks

Fixes rust-lang#57582.

r? @QuietMisdreavus

…apse-rules-to-trait-impls, r=Manishearth

Don't apply impl block collapse rules to trait impls

Fixes rust-lang#58147.

r? @QuietMisdreavus

…apin

Remove images' url to make it work even without internet connection

Needed for local std docs mainly.

cc @SimonSapin

r? @QuietMisdreavus