• First-class support for OPTIONS requests via OptionsAsync (#220)
• Support building & testing on Mac and Linux (#290 & #286, thx @nlowe )
• FlurlClient constructor for wrapping an existing HttpClient (#298)
• Public constructor for HttpCall so that fakes can be easily created (#304)
• BREAKING: IFlurlClientFactory implements IDisposable (#309)
• BUGFIX: Don't overwrite content headers when set explicitly (#256)
• BUGFIX: WithHeader assert failed when header had space (#307)