Add comments to methods with annotations but no implementation

Additionally, removed unused empty constructor

src/main/java/de/thm/arsnova/controller/SecurityExceptionControllerAdvice.java

@@ -62,16 +62,19 @@ public class SecurityExceptionControllerAdvice {
 	@ResponseStatus(HttpStatus.NOT_FOUND)
 	@ExceptionHandler(NotFoundException.class)
 	public void handleNotFoundException(final Exception e, final HttpServletRequest request) {
+		/* No implementation - handled solely by annotations */
 	}
 
 	@ResponseStatus(HttpStatus.UNAUTHORIZED)
 	@ExceptionHandler(UnauthorizedException.class)
 	public void handleUnauthorizedException(final Exception e, final HttpServletRequest request) {
+		/* No implementation - handled solely by annotations */
 	}
 
 	@ResponseStatus(HttpStatus.UNAUTHORIZED)
 	@ExceptionHandler(AuthenticationCredentialsNotFoundException.class)
 	public void handleAuthenticationCredentialsNotFoundException(final Exception e, final HttpServletRequest request) {
+		/* No implementation - handled solely by annotations */
 	}
 
 	@ExceptionHandler(AccessDeniedException.class)
@@ -95,30 +98,36 @@ public class SecurityExceptionControllerAdvice {
 	@ResponseStatus(HttpStatus.FORBIDDEN)
 	@ExceptionHandler(ForbiddenException.class)
 	public void handleForbiddenException(final Exception e, final HttpServletRequest request) {
+		/* No implementation - handled solely by annotations */
 	}
 
 	@ResponseStatus(HttpStatus.NO_CONTENT)
 	@ExceptionHandler(NoContentException.class)
 	public void handleNoContentException(final Exception e, final HttpServletRequest request) {
+		/* No implementation - handled solely by annotations */
 	}
 
 	@ResponseStatus(HttpStatus.BAD_REQUEST)
 	@ExceptionHandler(BadRequestException.class)
 	public void handleBadRequestException(final Exception e, final HttpServletRequest request) {
+		/* No implementation - handled solely by annotations */
 	}
 
 	@ResponseStatus(HttpStatus.PRECONDITION_FAILED)
 	@ExceptionHandler(PreconditionFailedException.class)
 	public void handlePreconditionFailedException(final Exception e, final HttpServletRequest request) {
+		/* No implementation - handled solely by annotations */
 	}
 
 	@ResponseStatus(HttpStatus.NOT_IMPLEMENTED)
 	@ExceptionHandler(NotImplementedException.class)
 	public void handleNotImplementedException(final Exception e, final HttpServletRequest request) {
+		/* No implementation - handled solely by annotations */
 	}
 
 	@ResponseStatus(HttpStatus.PAYLOAD_TOO_LARGE)
 	@ExceptionHandler(PayloadTooLargeException.class)
 	public void handlePayloadTooLargeException(final Exception e, final HttpServletRequest request) {
+		/* No implementation - handled solely by annotations */
 	}
 }

src/main/java/de/thm/arsnova/entities/transport/ImportExportSession.java

@@ -155,10 +155,6 @@ public class ImportExportSession {
 
 		private List<Answer> answers;
 
-		public ImportExportQuestion() {
-
-		}
-
 		public ImportExportQuestion(Question q) {
 			setType(q.getType());
 			setQuestionType(q.getQuestionType());

src/main/java/de/thm/arsnova/socket/ARSnovaSocketIOServer.java

@@ -230,7 +230,9 @@ public class ARSnovaSocketIOServer implements ARSnovaSocket, NovaEventVisitor {
 		server.addConnectListener(new ConnectListener() {
 			@Override
 			@Timed
-			public void onConnect(final SocketIOClient client) { }
+			public void onConnect(final SocketIOClient client) {
+				/* No implementation - only used for monitoring */
+			}
 		});
 
 		server.addDisconnectListener(new DisconnectListener() {