Graceful upgrade path for 0.28.

[tomchristie]

Suggested upgrade path for an upcoming 0.28 release...

We do have some backwards incompatible changes that we want to issue, but clearly need to minimise disruption to our userbase. Here's what we're currently looking at...

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Release Notes

The 0.28 release includes a limited set of backwards incompatible changes.

Backwards incompatible changes

SSL configuration has been significantly simplified.

• The verify argument no longer accepts string arguments for custom verify paths.
• The cert argument has now been removed.
• The SSL_CERT_FILE and SSL_CERT_DIR environment variables are no longer automatically used.

For users of the standard verify=True or verify=False cases this should require no changes.

For information on configuring more complex SSL cases, please see the SSL documentation.

Other updates

• The undocumented URL.raw property has now been deprecated, and will raise warnings. (Graceful upgrade path for 0.28. #3394)
• The deprecated proxies argument has now been removed. (Introduce new SSLContext API & escalate deprecations. #3319)
• The deprecated app argument has now been removed. (Introduce new SSLContext API & escalate deprecations. #3319)
• Ensure JSON request bodies are compact. (Ensure JSON representation is compact. #3363)
• Review URL percent escape sets, based on WHATWG spec. (Review URL percent escaping sets, from whatwg. #3371, Review urlescape percent-safe set, and use + behavior for form spaces. #3373)
• Ensure certifi and httpcore are only imported if required. (made dependencies on certifi and httpcore only load when required #3377)
• Treat socks5h as a valid proxy scheme. (add socks5h proxy support #3178)
• Cleanup Request() method signature in line with client.request() and httpx.request(). (Cleanup Request method parameter. #3378)

[tomchristie]

@encode/maintainers - Seems to me like a good point to make a release from. Any concerns or feedback on this set of release notes for 0.28? Reasonable balance here?