Bug-fix: Remove flows from voltha for deleted subscriber, even if sadis cannot
fetch information about the deleted subscriber.

Other changes:
      - Added a cli command that details subscribers that have actually been programmed in the data plane
      - Changed all cli commands to start with volt-* as all app cli commands should
      - removed DeviceIdCompleter from the 'olts' cli command as it is not needed
      - removed unused method, renamed another one, fixed some logs
      - S-tags are no longer 'DeviceVlans', so changed variable name

Change-Id: I7cfde850669ed5b581fbac3195f68da28c4514c3
diff --git a/app/src/main/java/org/opencord/olt/cli/ShowSubscribersCommand.java b/app/src/main/java/org/opencord/olt/cli/ShowSubscribersCommand.java
index 4298cd6..711d1fa 100644
--- a/app/src/main/java/org/opencord/olt/cli/ShowSubscribersCommand.java
+++ b/app/src/main/java/org/opencord/olt/cli/ShowSubscribersCommand.java
@@ -16,19 +16,20 @@
 
 package org.opencord.olt.cli;
 
+import java.util.Map;
+
 import org.apache.karaf.shell.commands.Command;
 import org.onlab.packet.VlanId;
 import org.onosproject.cli.AbstractShellCommand;
 import org.onosproject.net.ConnectPoint;
 import org.opencord.olt.AccessDeviceService;
 
-import java.util.Map;
-
 /**
- * Shows provisioned subscribers.
+ * Shows provisioned (configured) subscribers. The data plane flows for the
+ * subscribers may or may not have been programmed.
  */
-@Command(scope = "onos", name = "subscribers",
-        description = "Shows provisioned subscribers")
+@Command(scope = "onos", name = "volt-subscribers",
+        description = "Shows pre-provisioned subscribers")
 public class ShowSubscribersCommand extends AbstractShellCommand {
 
     private static final String FORMAT = "port=%s, svlan=%s, cvlan=%s";