Added support for displaying totals in the footer of the table list view.  This is not displayed by default since there are permission considerations with displaying totals (e.g. if someone performs a find for a single record then looks for the total on a column that they don't have permission to see for that record.  We can't just use the record permission because totals could be across many many records.  It is better to let the developer implement their own footer row and decide who gets to see it.