Gittrac #4171:  Committed the "basic" fix to V8_0-branch with new
DAGMAN_USE_OLD_DAG_READER knob as requested by TJ in code review.
Merge branch 'V8_0-branch' of /p/condor/repository/CONDOR_SRC into V8_0-branch
Fix sock_peer_to_string() to return formatted sinful string when known.