Smooth sortable

1. Use css transforms instead of position: relative! (Much more performant.)
2. Make this work on Mobile Safari.
3. Delegated event handling, so you can add items to the list and the sortable will still work.
4. Keyboard accessibility.
5. Bug: Sorting therhold changes by one or two pixels when you go over it.
6. Albert Einstein
7. Abraham Lincoln
   Had a loooooooooong
   Hat
   Hat
8. Marylin Monroe
9. Charlie Chaplin
   Maybe had two cats
10. Julius Caesar
11. Sigmund Freud