Add tests for CoreTaskExtensions.Finally methods
Add tests for 4 of 8 CoreTaskExtensions.Select methods
The IProgress<T> interface was not introduced until .NET 4.5
Add the Progress<T> default implementation of IProgress<T>
Fixup tests for Finally
Add tests for TaskBlocks.Using methods
Fixup tests for Select
Add tests for CoreTaskExtensions.Then
Ignore TestResults folder
Add placeholders for remaining required tests (all call Assert.Inconclusive)