Flurl Versions Save

• Additional configuration enhancements for #770 (description updated).
• BREAKING: Refactored a shared interface (#773)

Full Changelog: https://github.com/tmenier/Flurl/compare/Flurl.Http.4.0.0-pre5...Flurl.Http.4.0.0-pre6

• BREAKING: Complete overhaul of Flurl's configuration system (#770)
• Use SocketsHttpHandler on supported platforms (#769)

Full Changelog: https://github.com/tmenier/Flurl/compare/Flurl.4.0.0-pre4...Flurl.Http.4.0.0-pre5

• First-class support for persisting and restoring CookieJar (#758)
• HTTP 2.0 support via Settings.HttpVersion (#639)
• BREAKING: ConfigureRequest renamed to WithSettings (#764)
• BREAKING: Eliminate Flurl's IHttpClientFactory (#736)
• BUGFIX: AllowRealHttp now reverts to original HttpClient, eliminating certain quirks (#683)
• BUGFIX: Prevent extra space added to Content-Type headers (#740)
• Flurl no longer disposes request message automatically, per best practices (#650)

Full Changelog: https://github.com/tmenier/Flurl/compare/Flurl.3.0.7...Flurl.Http.4.0.0-pre4

• AppendQueryParams method/overloads (#688), thx @Marusyk!
• BUGFIX: SetQueryParams with collection, duplicate keys should append not overwrite (#370)
• BUGFIX: False negatives with Url.IsValid (#462)

Full Changelog: https://github.com/tmenier/Flurl/compare/Flurl.3.0.7...Flurl.4.0.0-pre4

• JSON deserialization case-insensitive by default (#719)
• Removed circular redirect detection (#714)
• Fixed ShouldHaveCalled false negative with URL ending with ? (#721)

• Retain trailing ? or # if specified in original string (#734)

• Default GetStreamAsync to unbuffered behavior (#630, breaking)
• Drop WithClient extension methods (#590, breaking)
• Drop ConnectionLeaseTimeout setting (#703, breaking)
• Move CancellationToken to last arg everywhere that it isn't (#702, breaking)

• Drop dependency on Newtonsoft.Json in favor of System.Text.Json (#517)*
• Drop non-generic dynamic-returning JSON methods (#699)
• Update target frameworks (#544 )

*WARNING: Your code may fail in subtle ways after upgrading if it depends on things like serialization attributes or global settings from the Newtonsoft library. To continue to use Newtonsoft with Flurl.Http 4.0 and later, add and register this Newtonsoft serializer in your code.

• Create symbols package for upload to nuget.org (#601, thx @gitfool)
• BUGFIX: NullRefEx when no body specified in RespondWith (#606)
• Trim leading/trailing whitespace from header values (#623)

• Create symbols package for upload to nuget.org (#601, thx @gitfool)