Windows tests exit with non-zero return code

[EwanC]

When both Graph/RecordReplay/dotp_multiple_queues.cpp and Graph/RecordReplay/valid_no_end.cpp tests are run on a Windows system they fail due to returning a non-zero exit code. The executables otherwise run okay, but when the return code is checked with echo %errorlevel% it is non-zero.

We need to investigate and fix these fails

[EwanC]

Both these tests use two queues, which aren't guaranteed to have the same content unless we modify them to make it so. Will try that.