We moved the instance of smo::Mind to global scope. I suppose we'll
only support one instance of Mind per SMO process at least for now.
We now track the state of Mind threads' JOLT-waiting. This allows us
to centralize the Mind thread shutdown logic. Mind::finalizeReq()
now takes care of all Mind thread shutdown state logic by tracking
whether Mind threads need to be JOLTed first before being told to
exit.
hayodea
c457ee7aca