[reSIProcate] adding detach to ThreadIf

["Bruce Lowekamp" <lowekamp@xxxxxxxxxxxxx>]

To make rutil/ThreadIf a bit more generic (we're trying to use it for
some other purposes within our code and need this functionality, which
seems generally useful), would it be possible to add a detach() call
to ThreadIf?

(obviously I don't know what the equivalent call is in Win32)

Thanks,
Bruce


ThreadIf.hxx:
  // signals we will not join and should auto-cleanup
  void detach();

ThreadIf.cxx:
void
ThreadIf::detach()
{
#if !defined(WIN32)
  pthread_detach(mId);
#else
  assert(0);
#endif;
}