Bug 151960 Library element popup menu display is wrong.
1:Creat a libray, add a table to this libray. 2:public this library. 3:Creat a report design. 4:Open the library explore, drag the table to the layout editor. 5:Select the table row, copy the selection row. 6:Select other row, clik the right button of the mouse to popup the menu . The result:Paste action and insert copied column action is highlight.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ColumnBandAdapter.java
*            <code>true</code> if it is. Otherwise <code>false</code>.
	 * @return new cell instances
	 */
	protected List getCellsInSlot( SlotHandle handle, int columnIndex,
			boolean mustBeStartPosition )
	{
		List retValue = new ArrayList( );
		for ( int i = 0; i < handle.getCount( ); i++ )
		{
			RowHandle row = (RowHandle) handle.get( i );
			CellHandle cell = getCellsInRow( row, columnIndex,
					mustBeStartPosition );
			if ( cell != null )
				retValue.add( cell );
		}
		return retValue;
	}
	/**
	 * Returns the column number with a given cell.
	 * 
	 * @param cell
	 *            the cell to find.
	 * @return the column number of the given cell.
	 */
	abstract protected int getCellPosition( CellHandle cell );
	/**
	 * Returns a copied cell with the given row and column number.
	 * 
	 * @param row
	 *            the row