OPENDJ-1929 Code cleanup
* org.opends.guitools.controlpanel.ui.VLVIndexPanel.java
* org.opends.guitools.controlpanel.ui.AbstractVLVIndexPanel.java
* org.opends.guitools.controlpanel.ui.NewVLVIndexPanel.java
* org.opends.guitools.controlpanel.task.DeleteIndexTask.java
** Use List instead of ArrayList as declarative type
** Reformat
** Add final keyword
** Add @Override annotations
** Remove unecessary javadoc
* org.opends.guitools.controlpanel.task.Task.java
** In method getConfigCommandLineArguments():
*** Returns a List instead of ArrayList