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
*            whether the value should be written as CDATA.
	 */
	protected void writeProperty( DesignElement obj, String tag,
			String propName, boolean cdata )
	{
		PropertyDefn propDefn = obj.getPropertyDefn( propName );
		
		if ( propDefn == null )
			return;
		Object value = obj.getLocalProperty( getModule( ), propName );
		if ( value == null )
			return;
		String xml = propDefn.getXmlValue( getModule( ), value );
		if ( xml == null )
			return;
		if ( propDefn.isEncryptable( ) )
		{
			IEncryptionHelper helper = MetaDataDictionary.getInstance( )
					.getEncryptionHelper( );
			xml = helper.encrypt( xml );
		}
		if ( tag == null )
			tag = ModelUtil.getTagByPropertyType( propDefn );
		if ( propDefn.getTypeCode( ) == IPropertyType.SCRIPT_TYPE )
			cdata = true;
		writeEntry( tag, propDefn.getName( ), xml, cdata );
	}
	/**
	 * Writes the structure memeber.
	 *