Bug 165188 logging per report
Setting up a dedicated (birt) report server, which serves all our web apps, leads to a logging desaster. Birtegine logs all messages to one file. There's no info which rptdesign caused the logmessage or who (e.g. user) caused the logmessage. Retrieving who/which rpt caused some logmessage is not possible! There are two possible solutions: (a) prefixing each logmessage with a userdefineable message (task.setLogprefix("myprefix")) (b) set an outputstream for each task (task.setLoggingOutputStream(outputstream)) to split the huge logfile to many small pieces.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/EngineLogger.java
logger.setLevel( logLevel );
		
		
		if ( logger.getLevel( ) != Level.OFF )
		{
			createLogFile( logger );
		}
	}
	/**
	 * Stop BIRT Logging and close all of the handlers. This function should only by called by the main application that started BIRT.
	 * Note: Because of a Java API's bug, an additional .lck file will be created for each log file. 
	 * 		 Please see http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4775533 for detail.    
	 */
	public static void stopEngineLogging()
	{
		Logger logger = Logger.getLogger( BIRT_NAME_SPACE );
		assert (logger != null);
		
		Handler[] handlers = logger.getHandlers();
		if ( (handlers != null) &&
			 (handlers.length > 0) )
		{
			for ( int i=0; i<handlers.length; i++ )
			{
				handlers[i].close();
				logger.removeHandler( handlers[i] );
			}
		}
		
		logFileHandler = null;