Translate the plugin lang file into English and Spanish

[osarrat]

The plugin lang file plugins/auto/spip-pmb/lang/pmb_fr.php is only available in French. It should be translated in English and Spanish.

[osarrat]

The squelettes/lang/ritimo_fr.php file should also be translated.

[teraud]

Fichiers langues anglais et espagnol en places. Ça mérite peut-être une petite relecture.