Change the summary form's "Number of records" checkbox to radio buttons, with a description of the default sort order where possible.

#396380 by merlinofchaos, dereine and dagmar: Initial support for GROUP BY queriescvs add handlers/views_handler_sort_group_by_numeric.inccvs add handlers/views_handler_sort_group_by_numeric.inccvs add handlers/views_handler_sort_group_by_numeric.inccvs add handlers/views_handler_sort_group_by_numeric.inccvs add handlers/views_handler_sort_group_by_numeric.inccvs add handlers/views_handler_sort_group_by_numeric.inc