Fixes to spark-ec2 scripts

1. To change http port number to 5080 (Line 136 of httpd.conf), include this file in templates to make sure it gets copied during startup

2. Fix the setup-slave.sh call to match what we had in the old mesos-ec2 scripts. The spark-ec2 directory should be rsync'ed before calling setup-slave.sh on workers. The known_hosts comment from is not applicable as we still run setup-slave.sh on the master early on.