Bug 213126 Add support for DataEngine-leve dataset cache
In many cases the DataEngine-leve dataset cache is useful which ensure that a dataset is executed one time during rendering one report. To support this feature a new dataset property should be added. The Birt customer can choose whether this dataset need to be cached or not by setting the property in deisgn time.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
* (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.elements.ElementVisitor#visitMasterPage(org.eclipse.birt.report.model.elements.MasterPage)
	 */
	public void visitMasterPage( MasterPage obj )
	{
		super.visitMasterPage( obj );
		property( obj, IMasterPageModel.TYPE_PROP );
		
		String type = (String) obj.getLocalProperty( getModule( ),
				IMasterPageModel.TYPE_PROP );
		if ( DesignChoiceConstants.PAGE_SIZE_CUSTOM.equalsIgnoreCase( type ) )
		{
			property( obj, IMasterPageModel.HEIGHT_PROP );
			property( obj, IMasterPageModel.WIDTH_PROP );
		}
		property( obj, IMasterPageModel.ORIENTATION_PROP );
		property( obj, IMasterPageModel.TOP_MARGIN_PROP );
		property( obj, IMasterPageModel.LEFT_MARGIN_PROP );
		property( obj, IMasterPageModel.BOTTOM_MARGIN_PROP );
		property( obj, IMasterPageModel.RIGHT_MARGIN_PROP );
		writeStyle( obj );
		writeOverridenPropertyValues( obj );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.elements.ElementVisitor#visitStyledElement(org.eclipse.birt.report.model.core.StyledElement)
	 */
	public void visitStyledElement( StyledElement obj )