New: Prepare correct management of timezones

htdocs/admin/system/dolibarr.php

htdocs/cashdesk/deconnexion.php

htdocs/cashdesk/include/environnement.php

htdocs/cashdesk/index.php

htdocs/includes/.cvsignore

htdocs/langs/ca_ES/admin.lang

htdocs/langs/da_DA/admin.lang

htdocs/langs/de_DE/admin.lang

htdocs/langs/en_US/admin.lang

htdocs/langs/es_ES/admin.lang

htdocs/langs/fi_FI/admin.lang

htdocs/langs/fr_FR/admin.lang

htdocs/langs/fr_FR/main.lang

htdocs/langs/it_IT/admin.lang

htdocs/langs/nb_NO/admin.lang

htdocs/langs/nl_BE/admin.lang

htdocs/langs/nl_NL/admin.lang

htdocs/langs/pl_PL/admin.lang

htdocs/langs/pt_PT/admin.lang

htdocs/langs/ro_RO/admin.lang