Java: changes to MQException and MQDataException class logging

The logging functionality of the com.ibm.mq.MQException class, which wrote details of new MQExceptions to a log, has been removed for IBM® MQ 8.0.

The com.ibm.mq.MQException class historically wrote details of new MQExceptions to a log. The default log was System.err, but this default could be overridden by application code. The exceptions codes to be logged could be tailored by methods on the same class so that specific codes could be excluded and included.

Although the logging functionality has been removed, the relevant static public field MQEnvironment.log and the methods MQEnvironment.logInclude(Integer) and MQEnvironment.logExclude(Integer) have been retained for compatibility with existing code, but have no effect.

The com.ibm.mq.headers.MQDataException class has been amended in the same manner.