Spark: Update to current example standards, add GCS connector

* Pod -> ReplicationController, which also forced me to hack around
hostname issue on the master. (Spark master sees the incoming slave
request to spark-master and assumes it's not meant for it, since it's
name is spark-master-controller-abcdef.)

* Remove service env dependencies (depend on DNS instead).

* JSON -> YAML.

* Add GCS connector.

* Make example do something actually useful: A familiar example to
anyone at Google, implement wordcount of all of Shakespeare's works.

* Fix a minor service connection issue in the gluster example.

examples/spark/spark-gluster/spark-master-controller.yaml

@@ -3,7 +3,7 @@ apiVersion: v1
 metadata:
   name: spark-master-controller
   labels:
-    component: spark-master-controller
+    component: spark-master
 spec:
   replicas: 1
   selector:
@@ -22,7 +22,7 @@ spec:
             - mountPath: /mnt/glusterfs
               name: glusterfsvol
           resources:
-            limits:
+            requests:
               cpu: 100m
       volumes:
         - name: glusterfsvol

examples/spark/spark-gluster/spark-master-service.yaml

@@ -9,4 +9,4 @@ spec:
     - port: 7077
       targetPort: 7077
   selector:
-    component: spark-master-controller
+    component: spark-master

examples/spark/spark-gluster/spark-worker-controller.yaml

@@ -12,7 +12,7 @@ spec:
     metadata:
       labels:
         component: spark-worker
-        uses: spark-master-controller
+        uses: spark-master
     spec:
       containers:
         - name: spark-worker
@@ -23,7 +23,7 @@ spec:
             - mountPath: /mnt/glusterfs
               name: glusterfsvol
           resources:
-            limits:
+            requests:
               cpu: 100m
       volumes:
         - name: glusterfsvol