feat: spanish translation. Most of it, google translation

[aelesfer]

Part 1 of a process of translation of the game into spanish.
This first version has been made with google translate mostly, but will improve while testing the texts ingame.

[romovs]

Sorry for late reply,
Since it's an automatic translation, most likely it's far off from anything proper, and I am not entirely sure if that's a good idea to include something so preliminary in a public release.
If you just want to test or play with it for now while continuing working on it, then it might be better to just rename the translation files to *_ru.properties, drop them into l10n.jar, and switch the language to Russian in the client.