Bug 25909: Recent change to datatables JS in the OPAC causes errors

Bug 25909: Recent change to datatables JS in the OPAC causes errors

This patch reverts some changes made by Bug 25287 which prematurely
introduced the double-underscore i18n function. The i18n features
haven't been fully implemented in the OPAC.

Some lines are reverts to the previous version, and some are additions,
for instance where Bug 25287 introduced new DataTables features and a
new string translation is required.

In addition to i18n changes, the patch also reverts the default
configuration of DataTables in the OPAC so that the "dom" configuration
option is set back to "t." This turns off features like pagination
buttons, filters, etc. which were previously disabled by default.

Enabling these features requires revision to the OPAC CSS in order for
them to display well.

To test, apply the patch and view a page in the OPAC which includes a
DataTable. For instance: checkouts on the "your summary" page, serial
issues on the "full subscription history" page.

Tables should display correctly and sorting should work correctly. There
should be no other DataTables controls visible.

To test translatability:

To test, apply the patch and test that the correct strings are
translatable. In this example I'm testing fr-FR:

    - Update a translation:

      > cd misc/translator
      > perl translate update fr-FR

    - Open the corresponding .po file for the strings pulled from
      the templates  e.g.  misc/translator/po/fr-FR-opac-bootstrap.po
    - Locate strings pulled from bootstrap/en/includes/datatables.inc
      for translation, e.g.:

      #. SCRIPT
      #: opac-tmpl/bootstrap/en/includes/datatables.inc:4
      msgid "Copy to clipboard"
      msgstr ""

    - Edit the "msgstr" string however you want (it's just for testing)
    - Install the updated translation:

      > perl translate install fr-FR

Open the translated copy of datatables.inc and confirm that the
translated string appears.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>