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
{
	protected Logger logger;
	/**
	 * engine configuration object
	 */
	protected EngineConfig config;
	/**
	 * A helper object to carry out most ReportEngine jobs
	 */
	protected ReportEngineHelper helper;
	/**
	 * root script scope. contains objects shared by the whole engine.
	 */
	protected ScriptableObject rootScope;
	/**
	 * Constructor. If config is null, engine derives BIRT_HOME from the
	 * location of the engine jar file, and derives data driver directory as
	 * $BIRT_HOME/drivers. For a simple report with no images and links, engine
	 * will run without complaining. If the report has image/chart defined, the
	 * engine has to be configured with relevant image and chart handlers.
	 * 
	 * @param config
	 *            an engine configuration object used to configure the engine
	 */
	public ReportEngine( EngineConfig config )
	{
		this.config = config;
		
		logger = intializeLogger( );