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
appContext.putAll( sysAppContext );
		}
		if ( context != null )
		{
			appContext.putAll( context );
		}
		executionContext.setAppContext( appContext );
		StringBuffer logStr = null;
		if ( log.isLoggable( Level.FINE ) )
			logStr = new StringBuffer( );
		
		if ( !appContext.isEmpty( ) )
		{
			Set entries = appContext.entrySet( );
			for ( Iterator iter = entries.iterator( ); iter.hasNext( ); )
			{
				Map.Entry entry = (Map.Entry) iter.next( );
				if ( entry.getKey( ) instanceof String )
				{
					executionContext.registerBean( (String) entry.getKey( ),
							entry.getValue( ) );
					if ( logStr != null )
					{
						logStr.append( entry.getKey( ) );
						logStr.append( "=" );
						logStr.append( entry.getValue( ) );
						logStr.append( ";" );
					}
				}
				else