Bug 154828 Item from library contant user properties can't delete
Details: Item from library contant user properties can't delete Step: 1.New a library. 2.Add a label and add a user properites. 3.Public the library. 4.New a report design and use the library 5.Drop the label from library explorer into layout. 6.Try to delete it. Actual result: The label from library contant user properties can't be delete. Exception reuslt: The label can be delete.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ContentCommand.java
/**
	 * Constructs the content command with container element.
	 * 
	 * @param module
	 *            the module
	 * @param container
	 *            the container element
	 */
	public ContentCommand( Module module, DesignElement container )
	{
		super( module, container );
	}
	/**
	 * Adds a new element into a container and specifies the position in the
	 * container. Virtually all elements must reside in a container. Containers
	 * are identified by a container ID. The application creates the element
	 * object, then adds it to the container here. The undo of this operation
	 * effectively deletes the element.
	 * 
	 * @param content
	 *            the element to add
	 * @param slotID
	 *            the slot in which to add the component
	 * @param newPos
	 *            the position index at which the content to be inserted. If
	 *            it's -1, the content will be inserted at the end of the slot.
	 * @throws ContentException
	 *             if the content cannot be added into this container.
	 * @throws NameException
	 *             if the name of the content exists in name space.