[x] integrates DI support and samples from @mchaloupka (squashed version of PR #2 addressing issue #1)
[x] integrates a functional layer and samples on top of Miloš's work from @michalkovy (squashed version of PR #5)
[x] Includes support for having tupled results from a Step function entering multiple values into the container (from @michalkovy)
[x] Adds a sample showing how the batteries-included DI support can be substituted with a common DI container (Autofac)
[x] Includes key tweaks from @mchaloupka of the External ServiceProvider integration
[x] Illustrates how the external Service Provider can be wired to xUnit's Shared Context in order to have a component be created/destroyed once per test run
[x] Includes thorough README documentation on the DI mechanism from @mchaloupka
This PR