We add the new Qutex acquisision history tracker that allows us
to dynamically detect qutex gridlocks. We've integrated it into
LockerAndInvoker::operator() in a preliminary way.
We also moved all of the trace*ForGridlockOn() methods into the
new QutexAcquisitionHistoryTracker singleton class. They're
more appropriately located there. They're still unimplemented
though.