Bug 14671: Allow correct translation of CAS authentication

Bug 14671: Allow correct translation of CAS authentication

In authentication pages with CAS, the use of acronym or abbr tags does not allow a correct translation of the text.
See http://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=5983#c7

It does not help a lot end users to know that CAS is Central Authentication Service, I think. Now one can custom the login page with NoLoginInstructions syspref to describe how to use the authentication.

This patch removes the use of acronym and abbr is authentication pages.

Test plan (example with fr-FR locale) :
- Without patch
- Update translation files : cd misc/translator ; perl translate update fr-FR
- You see in fr-FR-opac-bootstrap.po : msgid "If you have a "
- Is is translated in : msgstr "Si vous avez un compte "
- Apply patch
- Update translation files : cd misc/translator ; perl translate update fr-FR
- You see in fr-FR-opac-bootstrap.po : msgid "If you have a CAS account, %s please "
- You can now translate it : msgstr "Si vous avez un compte CAS, %s veuillez "
- Same test for intranet authentication page
- Install the translation : cd misc/translator ; perl translate install fr-FR
- Look at the result

Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
Works as advertised. Tranlated OK, tested in spanish es-ES

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>