LP1164674 - OPAC - Too easy to delete a list

Added an onClick action to prompt for confirmation before
deleting a list.

Signed-off-by: Kyle Tomita <ktomita@catalystitservices.com>
Signed-off-by: Dan Wells <dbw2@calvin.edu>
Move list delete check from onclick to onsubmit

Cause Brendan Eich says it's better :)

Signed-off-by: Dan Wells <dbw2@calvin.edu>
Signed-off-by: Remington Steed <rjs7@calvin.edu>