implemented editing of list credentials for admin/owner, fixed bug:

if login fails due to wrong auth, it is no longer repeated. instead, the list is disabeld

src/main/java/de/srsoftware/widerhall/mail/ImapClient.java

@@ -14,6 +14,7 @@ public class ImapClient {
     private static final Logger LOG = LoggerFactory.getLogger(ImapClient.class);
     private final int port;
     private final String host, username, password, folderName;
+    private final ProblemListener problemListener;
     private IMAPFolder inbox;
     private ListeningThread listeningThread;
     private Heartbeat heartbeat;
@@ -47,6 +48,7 @@ public class ImapClient {
                     openInbox();
                 } catch (MessagingException e){
                     LOG.warn("Connection problem:",e);
+                    problemListener.onImapException(e);
                 }
             }
         }
@@ -127,12 +129,13 @@ public class ImapClient {
         }
     }
 
-    public ImapClient(String host, int port, String username, String password, String folderName) {
+    public ImapClient(String host, int port, String username, String password, String folderName,ProblemListener listener) {
         this.host = host;
         this.port = port;
         this.username = username;
         this.password = password;
         this.folderName = folderName;
+        this.problemListener = listener;
     }
 
     public ImapClient addListener(MessageHandler messageHandler) {