mgcb.exe process left running if pipeline tool crashes

[jamesford42]

If the pipeline tool crashes for some reason, it will leave any running mgcb.exe process stranded and still running (this may also occur if you launched from the IDE and 'stop debugging').

There should be a mechanism to avoid this -- on windows i am certain that there is, it involves making some win32 pinvokes to register the process as a child and windows closes it automatically.