Fix "username" property on Windows 7 which, for certain processes, returns "None\None", in which case AccessDenied gets raised instead. This matches procexp behavior which fills such process with a "<access denied>" string.
Fix "username" property on Windows 7 which, for certain processes, returns "None\None", in which case AccessDenied gets raised instead. This matches procexp behavior which fills such process with a "<access denied>" string.

git-svn-id: 9f18dd852162ff6c59c5533c0914e9cf81af9e7c@650 d8a29897-7e4b-0410-a74a-8bb4c295346f

hybridlogic/psutil,hybridlogic/psutil,tamentis/psutil,hybridlogic/psutil,tamentis/psutil