Improvements to robustness of CThreadPool. Rationalised CThreadPool a bit, so that only the main thread is used for thread death notifications. This means that the death of parent threads no longer causes a panic when the child threads is shut down.

EXPORTS
	?ImplementationGroupProxy@@YAPBUTImplementationProxy@@AAH@Z @ 1 NONAME ; struct TImplementationProxy const * ImplementationGroupProxy(int &)
	?KAutoStartFshell@@3HB @ 2 NONAME ; int const KAutoStartFshell