Add support for user-specified job name prefix
Add support for user-specified job name prefix

cloudera/dist_test,xiao-chen/dist_test,xiao-chen/dist_test,xiao-chen/dist_test,cloudera/dist_test,umbrant/dist_test,xiao-chen/dist_test,umbrant/dist_test,cloudera/dist_test,umbrant/dist_test,cloudera/dist_test,umbrant/dist_test