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
* Returns the number of columns in the element.
	 * 
	 * @return the number of columns in the element
	 */
	protected abstract int getColumnCount( );
	ColumnBandAdapter( )
	{
		
	}
	/**
	 * Returns the column index that is the start column index of the
	 * <code>target</code>.
	 * 
	 * @param target
	 *            the column to find
	 * @return a column index
	 */
	protected static int getColumnStartPos( ColumnHandle target )
	{
		SlotHandle columns = target.getContainerSlotHandle( );
		int colStartPos = 1;
		int colPosInSlot = columns.findPosn( target );
		for ( int i = 0; i < colPosInSlot; i++ )
		{
			ColumnHandle col = (ColumnHandle) columns.get( i );
			colStartPos += col.getRepeatCount( );
		}
		return colStartPos;
	}
	/**