Bug 145520 Group name will not show up in group list if the group use default name and key expression has no value
Description: Group name will not show up in group list if key expression has no value. Steps to reproduce: 1. Insert a table into report, bind it to a data set 2. Switch to property editor -> groups 3. Click on add button to open new group dialog, then press ok button Expected result: A new group with default name will be added to group list Actual result: A new group is added to group list, but without group name. But when let group tab lost focus and get focus again, you can see the group name.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ContentCommand.java
* @param to
	 *            The new container.
	 * @param toSlotID
	 *            The slot within the new container.
	 * @throws ContentException
	 */
	public void move( DesignElement content, int fromSlotID, DesignElement to,
			int toSlotID ) throws ContentException
	{
		doMove( content, fromSlotID, to, toSlotID, -1 );
	}
	/**
	 * 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 void movePosition( DesignElement content, int slotID, int newPosn )