The Comma-separated Selector widget allow
the user to render a comma separated string of values as two select fields:
one with "remaining values", and one with the "selected
values".
The widget inserts buttons to allow you to select
all elements and to move the selection from one field to the other.
The "Selected Values" field has buttons
for ordering the selection. The user selects an entry and can then move
it up or down one place simply by clicking on the right hand arrows.
Please see the below picture to better understand the behavior.
