We add the skeleton of a correct history tracer for gridlocks. The
previous history tracer made the incorrect assumption that we would
find the foreign sequence's currently desired LockSet inside of the
lockvoker that it has stored inside of Qutex::currOwner.
This ensures that the Lockvoker object we access from currOwner
remains valid past the lifetime of the Lockvoker object that
gets copied and invoked by boost::asio
We added the code to trace all the contins linked to a particular
Lockvoker, into SerializedAsyncContinuation. This basically
ensures that we'll almost never deal with a deadlock. So cool.
hayodea