Bug 15492: Make existing code aware of new self_check* permissions

Bug 15492: Make existing code aware of new self_check* permissions

This patch makes the existing code for SCO use the new permissions schema
for self check modules. Specifically addresses this change:

  circulate  => self_checkout
becomes
  slef_check => self_checkout_module

about.pl checks are dejusted too.

get_template_and_user gets refactored to avoid code duplication and the
conditions are adjusted for the new permissions.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>