Bug 121498 When datasource/dataset deleted, the datasource/dataset property binding element haven't been deleted
When deleted the datasource/dataset, the datasource/dataset property binding element haven't been deleted. Expected result: This operation must be a transaction.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ContentCommand.java
/*******************************************************************************
 * Copyright (c) 2004 Actuate Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http:www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *  Actuate Corporation  - initial API and implementation
 *******************************************************************************/
package org.eclipse.birt.report.model.command;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import org.eclipse.birt.report.model.activity.AbstractElementCommand;
import org.eclipse.birt.report.model.activity.ActivityStack;
import org.eclipse.birt.report.model.api.activity.SemanticException;
import org.eclipse.birt.report.model.api.command.ContentException;
import org.eclipse.birt.report.model.api.command.ExtendsException;
import org.eclipse.birt.report.model.api.command.NameException;
import org.eclipse.birt.report.model.api.command.UserPropertyException;
import org.eclipse.birt.report.model.api.core.UserPropertyDefn;
import org.eclipse.birt.report.model.api.metadata.IElementDefn;
import org.eclipse.birt.report.model.api.util.StringUtil;
import org.eclipse.birt.report.model.core.BackRef;