harvesthq/chosen — pull request #982 by MattCBowman (2013-01-12 21:02:08+00:00)
Title: Allow user to deselect from single select chosen container from the keyboard when allow_single_deselect is true

If the chosen container has allow_single_deselect turned on and the user is operating from the keyboard, this fix will allow them to deselect without using the mouse. They simply select nothing and press return, which clears the currently selected item.