Allow Start and End Dates to be Moved Simultaneously

Modify the sliders in Discover so that you can drag the center between the two selections to have a moving range.  That way if you want to look at a 3 day period then another 3 day period without doing a compare you can just drag the date range block all at once.  This would also save on server calls since normally Discover will call the server when you move the start date and again when you move the end date.