[qmtest] derivation issues?

[eichin at metacarta.com]

> in Run, before calling MyShellScriptTest.Run, no problems there... but
> substituting on self.stdout (etc.) wasn't working -- this would fix
> that?

Oh, ignore me, that was one of those "looking for subtle class
hierarchy issues, and missing that I'd used the wrong variable name"
(using
self.stdin = self.__PerformSubstitutions(context, self.realstdin)
worked a lot better :)