The user-facing changes effected by this commit are:
* The 'http::Cookies<'_>' guard is now '&http::CookieJar<'_>'.
* The "one-at-a-time" jar restriction is no longer imposed.
* 'CookieJar' retrieval methods return 'http::CookieCrumb'.
* The 'private-cookies' feature is now called 'secrets'.
* Docs flag private cookie methods with feature cfg.
* Local, async request dispatching is never serialized.
* 'Client::cookies()' returns the tracked 'CookieJar'.
* 'LocalResponse::cookies()' returns a 'CookieJar'.
* 'Response::cookies()' returns an 'impl Iterator'.
* A path of '/' is set by default on all cookies.
* 'SameSite=strict' is set by default on all cookies.
* 'LocalRequest::cookies()' accepts any 'Cookie' iterator.
* The 'Debug' impl for 'Request' prints the cookie jar.
Resolves#1332.
The bulk of the changes in this commit are for creating an
'ErrorHandler' trait that works like the 'Handler' trait, but for
errors. Furthermore, Rocket's default catcher now responds with a JSON
payload if the preferred 'Accept' media type is JSON.
This commit also fixes a bug in 'LocalRequest' where the internal
'Request' contained an correct 'URI'.
This commits makes the following high-level changes:
* 'ShutdownHandle' is renamed to 'Shutdown'.
* 'Rocket::shutdown_handle()' is renamed to 'Rocket::shutdown()'.
* '#[launch]` is preferred to '#[rocket::launch]'.
* Various docs phrasings are improved.
* Fixed various broken links in docs.
This commits rearranges top-level exports as follows:
* 'shutdown' module is no longer exported.
* 'Shutdown' is exported from the crate root.
* 'Outcome' is not longer exported from the root.
* 'Handler', 'ErrorHandler' are no longer exported from the root.