change draggable grip, fix two small bugs

- implemented the generally more well-received “nubs” dragging grip as
seen on Gmail’s interface & others (here’s it in better-history:
http://cl.ly/V2oy , and here’s it in gmail: http://cl.ly/V2G9 )

- fixed a small bug where the ghost tooltip would show up on the day
result page after you’ve released the mouse

- added prompt_delete tooltip to the search values