Fix intermittent shared_port errors on MacOS. #4094

Problem was new code to not fork the shared_port was closing
the socket being passed BEFORE receiving an ack from the endpoint.
This caused intermittent failures on MacOS.  The problem was
that daemonCore was closing the socket because the KEEP_STREAM
return value was not being properly propagated.
Merge branch 'V8_1_4-tt_shared_port-branch' into V8_1_4-branch
Merge branch 'V8_1_4-branch' of ssh://ingwe.cs.wisc.edu/p/condor/repository/CONDOR_SRC into V8_1_4-branch