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/EngineTask.java
* Defines an engine task that could be executed, debugged (runs step by step),
 * inform caller for progress, etc.
 */
public abstract class EngineTask implements IEngineTask
{
	protected static int id = 0;
	protected String pagination;
	protected final static String FORMAT_HTML = "html";
	/**
	 * is cancel called
	 */
	protected boolean cancelFlag;
	protected int runningStatus;
	/**
	 * a reference to the report engine
	 */
	protected IReportEngine engine;
	/**
	 * logger used to output the message
	 */
	protected Logger log;
	/**
	 * Comment for <code>locale</code>
	 */
	protected Locale locale = Locale.getDefault( );
	/**
	 * the execution context
	 */
	protected ExecutionContext executionContext;
	/**