First cut of thread pools in fshell. Not fully working yet. Removed 4 overloads of CCommandBase::RunCommand[L] that are no longer used at all, and changed one more to not be exported as it's only used internally to iocli.dll. Added a thread pool (CThreadPool) to fshell so that thread commands no longer have to spawn a new thread every time they run. As part of this, CCommandWrapperBase now derives from CActive so that CThreadCommand can use its CActive-ness. CThreadCommand rejigged quite a bit to use CThreadPool (via MTaskRunner interface).

EXPORTS
	??0RExtraBtrace@@QAE@XZ @ 1 NONAME ; RExtraBtrace::RExtraBtrace(void)
	?Handle@RExtraBtrace@@QBEHXZ @ 2 NONAME ; int RExtraBtrace::Handle(void) const
	?EnableProfiling@RExtraBtrace@@QAEHH@Z @ 3 NONAME ; int RExtraBtrace::EnableProfiling(int)
	?Connect@RExtraBtrace@@QAEHXZ @ 4 NONAME ; int RExtraBtrace::Connect(void)
	?Close@RExtraBtrace@@QAEXXZ @ 5 NONAME ; void RExtraBtrace::Close(void)