Bug 19994: Used Modern::Perl in Authorities perl scripts

Bug 19994: Used Modern::Perl in Authorities perl scripts

Test plan:
1. Review code of the following files and confirm that 'use Modern::Perl;' is used in place of
'use strict; use warnings;'

auth_finder.pl
authorities-home.pl
authorities.pl
blinddetail-biblio-search.pl
detail-biblio-search.pl
detail.pl
export.pl
merge.pl
merge_ajax.pl

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit 843c4a4bae760754d96867d2596bc78651910c8e)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>