Bug 188829 Move the item ,the trans of the model don't close.
1:New report design. 2:Add a Embedded image. 3:Add another imge , then drag the second imge to the first position. 4:Change the size of the first image. Expected: Image change the size. Now: Image size don't change.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/AbstractContentCommand.java
/**
	 * Moves an element from one position to another within the same slot.
	 * <p>
	 * For example, if a slot has A, B, C elements in order, when move A element
	 * to <code>newPosn</code> with the value 2, the sequence becomes B, A, C.
	 * 
	 * 
	 * @param content
	 *            The element to move.
	 * @param slotID
	 *            The slot that contains the element.
	 * @param newPosn
	 *            The new position within the slot. Note that the range of
	 *            <code>newPos</code> is from 0 to the number of element in
	 *            the slot with the ID <code>slotID</code>.
	 * @throws ContentException
	 *             if the content cannot be moved to new container.
	 */
	public final void movePosition( DesignElement content, int newPosn )
			throws ContentException
	{
		assert content != null;
		if ( eventTarget != null && !( this instanceof ContentElementCommand ) )
		{
			ContentElementCommand attrCmd = new ContentElementCommand( module,
					focus );
			attrCmd.movePosition( content, newPosn );
			return;
		}
		checkBeforeMovePosition( content, newPosn );