Deleting these lines restores the delete all button:
Code:
#saves-clear {
display: none;
}
Optionally put /* before and */ after to just make it a comment so that you can later restore the lines by removing /* and */
Edit: I now understand why it was removed. It is super easy to accidentally click on it and since it has no extra confirmation, it instantly wipes all your saves (including the daily auto save) and then you are completely screwed.
A better option for people, who saves a lot, it is probably better to routinely click on save to disk and only use the normal save slots when you want to repeatedly save scum something specific and then just get rid of the 1-2 normal saves after you are done.