include jobid in Executor commandline args

For whatever reasons, we've observed that sometimes the StandaloneExecutorBackend process doesn't die when a spark context finishes.  Obviously we'd like to eliminate that from happening in the first place, but in the meantime we just need an automated way to kill these rogue processes.

If the command line args include the jobid for each StandaloneExecutorBackend, then we can use `jps` to find the jobid of all the executors, and filter out those that the master doesn't know about.