Renamed methods in metacontactlist classes for better intuitivity

src/net/java/sip/communicator/impl/gui/main/contactlist/ContactListTree.java

@@ -212,8 +212,8 @@ private ContactNode contains(  ContactNode parentNode,
 				
 				MetaContact currentContact = (MetaContact)node.getUserObject();
 				
-                if(currentContact.getDefaultContact().getAlias()
-						.equals(contact.getAlias())){
+                if(currentContact.getDefaultContact().getDisplayName()
+						.equals(contact.getDisplayName())){
                     
                     return node;
 				}

src/net/java/sip/communicator/service/protocol/Contact.java

@@ -37,7 +37,7 @@ public interface Contact
      * @return a String that can be used for referring to this contact when
      * interacting with the user.
      */
-    public String getAlias();
+    public String getDisplayName();
 
     /**
      * Returns a byte array containing an image (most often a photo or an avatar)