Bug 122854 There is redundant columns in "available columns" list in "export data" dialog.
Description: There is redundant columns in "available columns" list in "export data" dialog. Steps to reproduce: 1. Preview attached design in web viewer. 2. Select the table and click on "export" button. 3. There is a "detail" column name in "available columns" list which is not data set column.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/data/dte/ReportQueryBuilder.java
*            the DataSetHandle
		 * @return the filer array
		 */
		public ArrayList createFilters( DataSetHandle dataSet )
		{
			return createFilters( dataSet.filtersIterator( ) );
		}
		/**
		 * create filter array given a GroupHandle
		 * 
		 * @param group
		 *            the GroupHandle
		 * @return filter array
		 */
		public ArrayList createFilters( GroupHandle group )
		{
			return createFilters( group.filtersIterator( ) );
		}
		/**
		 * create one sort condition
		 * 
		 * @param handle
		 *            the SortKeyHandle
		 * @return the sort object
		 */
		private ISortDefinition createSort( SortKeyHandle handle )
		{
			SortDefinition sort = new SortDefinition( );
			sort.setExpression( handle.getKey( ) );
			sort.setSortDirection( handle.getDirection( ).equals(