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.tests/test/org/eclipse/birt/report/model/parser/TabularCubeParserTest.java
{
		private String propName = null;
		private int eventType = -1;
		public void elementChanged( DesignElementHandle focus,
				NotificationEvent ev )
		{
			eventType = ev.getEventType( );
			assert eventType == NotificationEvent.PROPERTY_EVENT;
			propName = ( (PropertyEvent) ev ).getPropertyName( );
		}
		MyListener( )
		{
		}
		String getPropName( )
		{
			return propName;
		}
		int getEventType( )
		{
			return eventType;
		}
		void reset( )
		{
			propName = null;
			eventType = -1;
		}
	}
}