Update spanish translation
Update spanish translation

I'm not sure about the accents, I left them verbatim (e.g. "Más") but I think I should replace them with XML encodings (sorry, XML newbie here).

Also, this has "issue" translated as "tema", while I think it should be "edicion" or "número" but I don't have an Android phone/tablet to test the funtcionality.
astagi/magpi-android,astagi/magpi-android