redirecting the unittests error output

[Mike Parker via Digitalmars-d-learn]

[1] 
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/redirection.mspx?mfr=true
[2] 
https://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/start.mspx?mfr=true