Bug 198839 Hide element on master page works only for PDF output
1. Insert any element (grid, label, image, text) in the header or footer of the master page. 2. Use the Visibility property to hide the element for all outputs. Expected result: Element does not appear in any of the output formats. Actual result: The element is hidden only in PDF.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/EngineTask.java
* the execution context
	 */
	protected ExecutionContext executionContext;
	/**
	 * task identifier. Could be used for logging
	 */
	protected int taskID;
	protected IReportRunnable runnable;
	/**
	 * options used to render the report design.
	 */
	protected IRenderOption renderOptions;
	/**
	 * emitter id
	 */
	protected String emitterID;
	/**
	 * does the parameter has been changed by the user.
	 */
	protected boolean parameterChanged = true;
	/**
	 * The parameter values that the caller has set explicitly
	 */
	protected HashMap inputValues = new HashMap( );
	/**
	 * The parameter values that will be used to run the report. It is a merged
	 * map between the input value and the default values.
	 */
	protected HashMap runValues = new HashMap( );
	/**