Add configuration knob for turning off new POST behavior
Add configuration knob for turning off new POST behavior

===GT=== #2057
===VersionHistory===
	Add DAGMAN_POST_IGNORE_PRE, which defaults to true. If false, then
	DAGman will revert to the old behavior, where a POST script does not
	run if the PRE script fails.

djw8605/condor,bbockelm/condor-network-accounting,mambelli/osg-bosco-marco,mambelli/osg-bosco-marco,zhangzhehust/htcondor,neurodebian/htcondor,djw8605/condor,bbockelm/condor-network-accounting,bbockelm/condor-network-accounting,mambelli/osg-bosco-marco,mambelli/osg-bosco-marco,djw8605/condor,djw8605/htcondor,htcondor/htcondor,djw8605/htcondor,bbockelm/condor-network-accounting,neurodebian/htcondor,zhangzhehust/htcondor,htcondor/htcondor,djw8605/htcondor,htcondor/htcondor,zhangzhehust/htcondor,djw8605/htcondor,htcondor/htcondor,bbockelm/condor-network-accounting,bbockelm/condor-network-accounting,zhangzhehust/htcondor,djw8605/htcondor,neurodebian/htcondor,djw8605/htcondor,neurodebian/htcondor,djw8605/htcondor,neurodebian/htcondor,mambelli/osg-bosco-marco,bbockelm/condor-network-accounting,djw8605/htcondor,djw8605/condor,mambelli/osg-bosco-marco,htcondor/htcondor,zhangzhehust/htcondor,mambelli/osg-bosco-marco,neurodebian/htcondor,htcondor/htcondor,djw8605/condor,djw8605/htcondor,zhangzhehust/htcondor,zhangzhehust/htcondor,neurodebian/htcondor,htcondor/htcondor,zhangzhehust/htcondor,djw8605/condor,djw8605/condor,zhangzhehust/htcondor,htcondor/htcondor,djw8605/condor,neurodebian/htcondor,bbockelm/condor-network-accounting,neurodebian/htcondor,mambelli/osg-bosco-marco