add ability to customize default printers

[slav]

"run" and "runParallel" customize TestPrinters.Default and use it to print outputs for failed and exceptions. It would be nice to provide a way to either customize TestPrinters.Default or allow run/runParallel take custom TestPrinters.

My goal is to have verbose printing and print information about passed tests.

It would also be nice to somehow print progress. Perhaps pass to BeforeRun # of test about to be run / # of tests total?

[wallymathieu]

Yes, this would make sense.

[wallymathieu]

I've added additional functions in order to simplify this scenario. You can also look at how it's done in the teamcity implementation.

[wallymathieu]

https://github.com/mausch/Fuchu/blob/4cae84092d8832579ab01b68fa7781c65ee7c34f/Fuchu/Fuchu.fs#L608-L613

See for instance the runParallelPrint. I had the same need as you when I did the Fable integration.