condor_q should not try non-forking protocol w/ v8.1.4 schedd. #4111

The v8.1.4 schedd as released does not understand the new protocol,
only v8.1.5 and above has it.
Merge branch 'V8_1_5-branch' of ssh://ingwe.cs.wisc.edu/p/condor/repository/CONDOR_SRC into V8_1_5-branch
change to default value of NEGOTIATOR_USE_WEIGHTED_DEMAND is now documented
 #4238
Merge branch 'V8_1_5-branch'