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
if ( renderOptions != null )
		{
			options.putAll( renderOptions.getOptions( ) );
		}
		
		IRenderOption allOptions = new RenderOption( options );
		executionContext.setRenderOption( allOptions );
		
		if ( IRenderOption.OUTPUT_FORMAT_PDF.equals( format ) )
		{
			Object renderContext = appContext
					.get( EngineConstants.APPCONTEXT_PDF_RENDER_CONTEXT );
			if ( renderContext == null )
			{
				PDFRenderOption pdfOptions = new PDFRenderOption( allOptions );
				PDFRenderContext pdfContext = new PDFRenderContext( );
				pdfContext.setBaseURL( pdfOptions.getBaseURL( ) );
				pdfContext.setEmbededFont( pdfOptions.isEmbededFont( ) );
				pdfContext.setFontDirectory( pdfOptions.getFontDirectory( ) );
				pdfContext.setSupportedImageFormats( pdfOptions
						.getSupportedImageFormats( ) );
				appContext.put( EngineConstants.APPCONTEXT_PDF_RENDER_CONTEXT,
						pdfContext );
			}
		}
		else
		{
			Object renderContext = appContext
					.get( EngineConstants.APPCONTEXT_HTML_RENDER_CONTEXT );
			if ( renderContext == null )