[EC2] [SPARK-6600] Open ports in ec2/spark_ec2.py to allow HDFS NFS gateway

Authorizes incoming access to master on the ports required to use the hadoop hdfs nfs gateway from outside the cluster.

Author: Florian Verhein <florian.verhein@gmail.com>

Closes #5257 from florianverhein/master and squashes the following commits:

72a586a [Florian Verhein] [EC2] [SPARK-6600] initial impl

ec2/spark_ec2.py

@@ -456,6 +456,13 @@ def launch_cluster(conn, opts, cluster_name):
         master_group.authorize('tcp', 50070, 50070, authorized_address)
         master_group.authorize('tcp', 60070, 60070, authorized_address)
         master_group.authorize('tcp', 4040, 4045, authorized_address)
+        # HDFS NFS gateway requires 111,2049,4242 for tcp & udp
+        master_group.authorize('tcp', 111, 111, authorized_address)
+        master_group.authorize('udp', 111, 111, authorized_address)
+        master_group.authorize('tcp', 2049, 2049, authorized_address)
+        master_group.authorize('udp', 2049, 2049, authorized_address)
+        master_group.authorize('tcp', 4242, 4242, authorized_address)
+        master_group.authorize('udp', 4242, 4242, authorized_address)
         if opts.ganglia:
             master_group.authorize('tcp', 5080, 5080, authorized_address)
     if slave_group.rules == []:  # Group was just now created