Add Spanish translation by VMX and Firefox11

 * Source: http://forums.fortress-forever.com/showpost.php?p=447465&postcount=70 and http://forums.fortress-forever.com/showpost.php?p=447926&postcount=80

* Our font currently struggles with the extended ascii characters (doesn't draw them at all). Might want to resolve that before merging this.
* Not sure why Github detects these as binary; they do need to be encoded in UTF-16 LE with BOM, so that might be it, but it might also be due to the blank .gitattributes file. I ain't know.