* Add Test_CreateProcess_SpecialInherit
* Add traditional Test_HandleDuplication
* Make handle.dup() use a GetCurrentProcess() target while
handle.dup(handle.worker()) uses a non-pseudo handle.
* Add Test_Active_ScreenBuffer_Order
* Add Test_GetStdHandle_SetStdHandle
* Also test a STARTF_USESTDHANDLES process in
Test_Detach_Does_Not_Change_Standard_Handles.
* TestCommon.h is a convenience header for the test cases. It aliases
Remote{Worker,Handle} back to {Worker,Handle}, and it includes many
basic C/C++ headers, as well as the parts of the harness suitable for
test cases.