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/ReportEngine.java
/**
	 * creates a task to run a report to generate a report document
	 * 
	 * @param reportRunnable
	 *            the runnable report design object
	 * @return a task that runs the report
	 */
	public IRunTask createRunTask( IReportRunnable reportRunnable )
	{
		logger.log( Level.FINE,
				"ReportEngine.createRunTask: reportRunnable={0} ", reportRunnable );
		return helper.createRunTask( reportRunnable );
	}
	/**
	 * creates a task that renders the report to a specific output format.
	 * 
	 * @param reportDocument
	 *            a handle to an IReportDocument object
	 * @return a task that renders a report to an output format
	 */
	public IRenderTask createRenderTask( IReportDocument reportDocument )
	{
		logger.log( Level.FINE,
				"ReportEngine.createRenderTask: reportDocument={0} ", reportDocument );
		return helper.createRenderTask( reportDocument );
	}
	/**
	 * opens a report document and returns an IReportDocument object, from which
	 * further information can be retrieved.
	 *