Bug 188578 Add "displayColumnName" on TabularLevel
Add Property "displayColumnName" on TabbularLevel and corresponding APIs on handle. Property Type: expression.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
property( obj, IModuleModel.CREATED_BY_PROP );
		property( obj, IModuleModel.UNITS_PROP );
		property( obj, IModuleModel.BASE_PROP );
		property( obj, IModuleModel.INCLUDE_RESOURCE_PROP );
		resourceKey( obj, IModuleModel.TITLE_ID_PROP, IModuleModel.TITLE_PROP );
		property( obj, IDesignElementModel.COMMENTS_PROP );
		resourceKey( obj, IModuleModel.DESCRIPTION_ID_PROP,
				IModuleModel.DESCRIPTION_PROP );
		writeUserPropertyDefns( obj );
		writeUserPropertyValues( obj );
		
		writeStructureList( obj, IModuleModel.PROPERTY_BINDINGS_PROP );
		
		writeStructureList( obj, IModuleModel.SCRIPTLIBS_PROP );
	}
	/**
	 * Visits the embedded images of the module.
	 * 
	 * @param obj
	 *            the module to traverse
	 */
	protected void writeEmbeddedImages( Module obj )
	{
		List list = (List) obj.getLocalProperty( obj, IModuleModel.IMAGES_PROP );
		if ( list != null && list.size( ) > 0 )
		{
			writer.startElement( DesignSchemaConstants.LIST_PROPERTY_TAG );
			writer.attribute( DesignSchemaConstants.NAME_ATTRIB,
					IModuleModel.IMAGES_PROP );
			for ( int i = 0; i < list.size( ); i++ )