fix ktest colorful output printing for non-ANSI terminals (issue #368)

This should fix it. We could do two things:

1. Replace `System.out.print[ln]` calls that prints colorful texts with `AnsiTerminal.out.print[ln]`
2. Just call `AnsiTerminal.systemInstall()` and use `System.out` as usual.

I choose second one. Please tell me if you see problems with that.

Note: We can also do that in krun. Currently it uses `AnsiTerminal.out` when it prints colorful text and we don't know for sure that no colorful text is printed using `System.out`.