Bug 27682: (follow-up) Make sure table is drawn with correct width

Bug 27682: (follow-up) Make sure table is drawn with correct width

The DataTables plugin calculates the width of the fixed header based on
the initial width of the corresponding table. Since these tables are
inside jQueryUI tabs, the width changes when the tabs are initialized
and jQueryUI adds its classes to the table's container.

This patch "manually" adds the relevant classes to the markup so that
the table's container is drawn with the right padding from the start.

Also fixed: Don't try to destroy "oldTableId" if the tableInit function
didn't pass an oldtabid.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>