Feature/seqware 1830 gatk hangs launcher

This is an optimization that speeds up launching of workflows with multiple forks in series by aborting recursion that would result in no changes. 

This is related to, but doesn't replace disabling ForkJoin which appears bugged with these kinds of workflows and simply hangs on job submission. See for the setting to toggle  
http://www.cloudera.com/content/cloudera-content/cloudera-docs/CDH4/latest/CDH4-Release-Notes/cdh4ki_topic_6_10.html