dlls/userenv: fixed stubs GetUserProfileDirectoryW/A (resend)

[Andreas Rosenberg]

Thanks for your hints, Paul.

I added some tests for the Ansi variant of the function
and fixed the problem you mentioned.

>I also think that your addition of _GetAccountNameFromTokenW is holding the
>committing of this patch back, especially because you don't seem to use
that
>function.

I also added an additional comment, why this function is not used.
Maybe you didn't notice the comments later on. Hopefully this makes things
clearer.
Unfortunately I don't have enough knowledge to fix the LookupAccountSidW
which is the reason why I did not use it, and why I'm still using
GetUserName to make the function return a valid path.

Is it regarded bad style what I did here? Any suggestions otherwise?

Regards
  Andreas