Bug 4470 Patron search result pagination bar

Bug 4470 Patron search result pagination bar

Obviously, Koha global pagination function could be improved. This patch
do something which belongs to this function. A CPAN module like
Data::Page could help or be an inspiration... 3.4?

There is also room for improvement in they way resultset are
constructed. The whole set is retrieved and just a subset is displayed.
It impacts performances for libraries with a great number of patrons.
The right solution would be:

  - to find the resultset size with SELECT COUNT(*)
  - to retrieved the exact subset with LIMIT and OFFSET SQL arguments

Signed-off-by: Galen Charlton <gmcharlt@gmail.com>