Bug 21918: Update buttons on fines to match newer buttons

Bug 21918: Update buttons on fines to match newer buttons

This patch makes a number of changes to the "Pay fines" template, the
goal of which is to make the interface look better in general. Changes
include:

 - Styling the "Pay" and "Write off" buttons as Bootstrap buttons.
 - Adding DataTables sorting, searching, and filtering.
 - Adding a column showing the fine date.
 - Hide the "Add note" input, add a link to show it.
 - Add some missing "preventDefault" methods from events.
 - Add "Writeoff selected" to the buttons which are disabled when there
   is no checkbox selection.
 - The <tfoot> tag is now expected by the HTML validator to be after
   <tbody>, so this section has been moved to suppress validator errors.

To test, apply the patch and locate a patron who has multiple
outstanding fines.

 - Go to Fines -> Pay fines
 - Confirm that the table of fines is shown as a DataTable, with sorting
   on columns which have data.
 - Test columns settings in Administration -> Columns settings.
 - Confirm that fine dates are shown, and that sorting by this column
   works correctly.
 - Click an "Add note" link to show a note input field. Focus should be
   in the newly-displayed input.
   - Confirm that notes are still saved correctly when paying or writing
     off single or multiple fines.
   - Confirm that when the "add note" input is hidden, its contents are
     erased.
 - Uncheck all checkboxes by clicking the "Clear all" link at the top.
   The "Pay selected" and "Write off selected" buttons should become
   disabled.
   - Checking any checkbox should re-enable those buttons.
 - Test that the relocated "Apply" button (for outstanding credits)
   still works as expected.

Signed-off-by: Jose-Mario Monteiro-Santos <jose-mario.monteiro-santos@inLibro.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>