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
*            the property name of resource key
	 * @param resourceName
	 *            the property name of user-visible resource
	 */
	protected void resourceKey( IStructure struct, String resourceKey,
			String resourceName )
	{
		StructureDefn structDefn = (StructureDefn) struct.getDefn( );
		assert structDefn != null;
		StructPropertyDefn nameProp = (StructPropertyDefn) structDefn
				.getMember( resourceName );
		assert nameProp != null;
		StructPropertyDefn keyProp = (StructPropertyDefn) structDefn
				.getMember( resourceKey );
		assert keyProp != null;
		Object value = null;
		Object keyValue = null;
		if ( struct instanceof Structure )
		{
			value = ( (Structure) struct ).getLocalProperty( getModule( ),
					nameProp );
			keyValue = ( (Structure) struct ).getLocalProperty( getModule( ),
					keyProp );
		}
		else
		{
			assert struct instanceof UserPropertyDefn;
			value = ( (UserPropertyDefn) struct ).getLocalProperty(
					getModule( ), nameProp );
			keyValue = ( (UserPropertyDefn) struct ).getLocalProperty(