Related to JIRA PM-160
Related to JIRA PM-160

Calling invoke_monitord_for_sub_workflow at the beginning before statistics of workflow is calculated.
Handled the case where dagman start_time or end_time is not present in the jobstate.log

pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus