[reSIProcate] clean shutdown

[Daniel Pocock]

I'm just wondering if anyone can clarify the following issues, and maybe 
elaborate on them in the Wiki:

a) In a multi-threaded app, does the app have to call both 
DialogUsageManager::shutdown() and DumThread::shutdown()?  Should 
DialogUsageManager::shutdown() be called from within the DumThread 
thread of execution?  Will DumThread eventually manage all shutdown calls?

b) In the repro.cxx code, I notice that DumThread is shutdown after the 
StackThread.  Is there a recommended order for stopping the threads?