's;^\s+$;;' on all source files

And add checkstyle test for lines containing only whitespace characters.

smack-extensions/src/main/java/org/jivesoftware/smackx/pep/PEPManager.java

@@ -115,7 +115,7 @@ public class PEPManager {
         PEPPubSub pubSub = new PEPPubSub(item);
         pubSub.setType(Type.set);
         //pubSub.setFrom(connection.getUser());
- 
+
         // Send the message that contains the roster
         connection.sendStanza(pubSub);
     }

smack-extensions/src/main/java/org/jivesoftware/smackx/pep/packet/PEPEvent.java

@@ -48,7 +48,7 @@ public class PEPEvent implements ExtensionElement {
 
         this.item = item;
     }
-    
+
     public void addPEPItem(PEPItem item) {
         this.item = item;
     }

smack-extensions/src/main/java/org/jivesoftware/smackx/pep/packet/PEPItem.java

@@ -28,11 +28,11 @@ import org.jivesoftware.smack.packet.ExtensionElement;
  * @author Jeff Williams
  */
 public abstract class PEPItem implements ExtensionElement {
-    
+
     String id;
     abstract String getNode();
     abstract String getItemDetailsXML();
-    
+
     /**
     * Creates a new PEPItem.
     *
@@ -41,7 +41,7 @@ public abstract class PEPItem implements ExtensionElement {
         super();
         this.id = id;
     }
-    
+
      /**
     * Returns the XML element name of the extension sub-packet root element.
     * Always returns "x"

smack-extensions/src/main/java/org/jivesoftware/smackx/pep/packet/PEPPubSub.java

@@ -28,7 +28,7 @@ import org.jivesoftware.smack.packet.IQ;
  * @author Jeff Williams
  */
 public class PEPPubSub extends IQ {
-    
+
     public static final String ELEMENT = "pubsub";
     public static final String NAMESPACE = "http://jabber.org/protocol/pubsub";