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/ContentElementCommand.java
protected void doMovePosition( DesignElement content, int newPosn )
			throws ContentException
	{
		
		if ( !focus.isContainerMultipleCardinality( ) )
			return;
		ActivityStack stack = getActivityStack( );
		String label = ModelMessages
				.getMessage( MessageConstants.MOVE_ELEMENT_MESSAGE );
		stack.startTrans( label, getTransOption( ) );
		DesignElement toMove = makeLocalCompositeValue( content );
		super.doMovePosition( toMove, newPosn );
		stack.commit( );
	}
	/**
	 * The method to set property.
	 * 
	 * @param prop
	 *            the definition of the property to set.
	 * @param value
	 *            the new property value.
	 * @throws SemanticException
	 *             if the element is a template element and users try to set the
	 *             value of template definition to "null" or a non-exsiting
	 *             element
	 */
	protected void doSetProperty( ElementPropertyDefn prop, Object value )
			throws SemanticException
	{
		ActivityStack stack = getActivityStack( );