Translation ca_ES for 245 (pkp-lib submodule)

A brand new Catalan translation for OJS 2.4.5.
* Initial clean translation was extended with the missing literals suggested by the "translation module".
* Newlines and header comments (including copyright) were unified (as much as possible).
* Copyright was extended with a Credit label linked to the OJS "ca_ES" translation page.

This translation was done using CAT sotware by the students of the Tradumatica master.

------------
A few extra notes about the translation:
* Desdoblament de gènere a la síl·laba tònica.
* Tractament de "vos" quan ens dirigim a l'usuari.
* Imperatiu per a les accions que ha de fer el sistema.
* Canvi del terme "connector" a "mòdul".