Cancelable Reads

This release implements a cancelable input reader which allows user input to be read after a Program has exited. This means that you can now run multiple Programs in succession in a single application as well as generally read user input in other after a Program has exited in the context of a single application.

In addition, all Goroutines are now gracefully terminated before Program.Start() returns, resulting in reliable behavior between subsequent Programs.

This update has been a major undertaking by @erikgeiser, who built specific implementations for Linux, BSD/macOS, and Windows as well as a general purpose implementation for other flavors of unix.

Thoughts? Questions? We love hearing from you. Feel free to reach out on Twitter or The Fediverse.