Bug 199834 Enable access to IContent object in IReportItemPresentation layer
In IReportItemPresentation layer, the extended item may want to access properties from current IContent object, for example, bookmark, content style. So we need expose the content object in this layer.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/presentation/LocalizedContentVisitor.java
if ( image.getImageSource( ) == IImageContent.IMAGE_FILE
				|| image.getImageSource( ) == IImageContent.IMAGE_URL )
		{
			String strUri = image.getURI( );
			ReportDesignHandle reportDesign = context.getDesign( );
			URL uri = reportDesign
					.findResource( strUri, IResourceLocator.IMAGE );
			if ( uri != null )
			{
				image.setURI( uri.toExternalForm( ) );
			}
		}
		
		handleOnRender( image );
		processImage( image );
		return image;
	}
	protected void processImage( IImageContent image )
	{
		String altText = localize( image, image.getAltTextKey( ), image.getAltText( ) );
		image.setAltText( altText );
		String helpText = localize( image, image.getHelpKey( ), image.getHelpText( ) );
		image.setHelpText( helpText );
	}
	/**
	 * handle the template result.
	 * 
	 * @param foreignContent
	 */
	protected void processTemplateContent( IForeignContent foreignContent )