Add Spanish translation

Thank you for workin in Squeez.
I have completed the Spanish translation.
I'm using Squeez 1.0 downloaded from F-Droid, and when I toggle views (List/Grid), the program shows a "pop-up" message; "Switched to GridView" or "Switched to ListView", but I couldn't find those messages in the strings.xml file. Could it be that those messages are not internationalized?

Best regards.