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
writeSimplePropertyList( obj, IValueAccessControlModel.ROLES_PROP );
		writeSimplePropertyList( obj, IValueAccessControlModel.VALUES_PROP );
		property( obj, IValueAccessControlModel.PERMISSION_PROP );
		writer.endElement( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.elements.ElementVisitor#visitTabularCube(org.eclipse.birt.report.model.elements.olap.TabularCube)
	 */
	public void visitTabularCube( TabularCube obj )
	{
		writer.startElement( DesignSchemaConstants.TABULAR_CUBE_TAG );
		super.visitTabularCube( obj );
		property( obj, ITabularCubeModel.DATA_SET_PROP );
		writeStructureList( obj, ITabularCubeModel.DIMENSION_CONDITIONS_PROP );
		writer.endElement( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.elements.ElementVisitor#visitTabularDimension(org.eclipse.birt.report.model.elements.olap.TabularDimension)
	 */
	public void visitTabularDimension( TabularDimension obj )
	{
		writer.startElement( DesignSchemaConstants.TABULAR_DIMENSION_TAG );
		super.visitTabularDimension( obj );
		writer.endElement( );
	}
	/*