Fix selected checkboxes sticking (so that they will stick)

Because works and copies were not getting propagated into the search form, on a new search even though boxes were selected, because they weren't in the result hidden form, 'edit selected' was not enabled (because the page thinks that nothing has been selected).

I also fixed another bug where if a user clicks on a couple of checkboxes and then immediatly hits 'search' again, the checkboxes won't be checked.