visualization of quicksort now swaps values instead of changing them ind...

check out how quicksosrt swaps values in arrays - if you accept this, I'll get to work on:
  - adding selenium tests for this (and combinations of swapping ans setting values in array)
  - better visualization of markers for array (e.g: horizontal markers are not so great, when trying to show the range on which quicksort partition operates on)

I am also thinking on some configuring what granularity of sync a user want to see, eg: does he want to see all swaps, or just the state of the array, after each partition.