Use I/O traits and types from 'tokio-io' as much as possible.
A few adapters only exist in futures-io-preview and use
futures-tokio-compat as a bridge for now.
* body_string_wait and body_bytes_wait are removed; use `.await` instead
* `dispatch()` is now an async fn and must be .await-ed
* Add `#[rocket::async_test]` macro, similar in purpose to `tokio::test`
* Tests now use either `rocket::async_test(async { })` or
`#[rocket::async_test]` in order to `.await` the futures returned
from `dispatch()` and `body_{string,bytes}()`
* Update 'test.sh' to reflect the tests that should be passing.
Broken:
* Cloned dispatch and mut_dispatch() with a live previous response now both fail, due to a (partial) check for mutable aliasing in LocalRequest.
* Some tests are still failing and need example-specific changes.
This commit introduces the sealed `UriPart` marker trait as well as the
implementing `Path` and `Query` marker types, allowing for parts of a
URI to be distinguished at the type level. Consequently, `UriDisplay`
has been parameterized with `P: UriPart`, creating `UriDisplay<Path>`
and `UriDisplay<Query>`. The effect of this change is improved type
safely for URI rendering as well as the ability to omit rendering values
in query parts via `Option` and `Result`.
The `UriDisplay` derive was replaced by `UriDisplayQuery` and
`UriDisplayPath` which derive implementations for `UriDisplay<Path>`
and `UriDisplay<Query>`, respectively.
This commit also works around a rustdoc visibility issue by creating a
hidden `http::private` module.
Finally, this commit also removes the now vestigial use of the
`rustc_private` feature in codegen.
Fixes#827.