Alright, this is the big mother update.

This commit includes a ton of changes and fixes to the original Spanish translation. Some have been taken from the iOS version (which was just a cleanup), others were done by myself.

I've reorganized the entire file per missions and sections just so I could know where I was looking at.

There's too much changes to list them, so here's the short version:
 - Retranslated and naturalized a lot of overly literal translations.
 - Fixed some uppercasing and lowercasing issues in the menus.
 - Shortened some subtitle translations that appear in a very short span of time so they are readable by the player.
 - This translation is European Spanish based, just like the original one and following Rockstar's policy up until GTAV. However, I tried to "neutralize" characters that are Latino American (El Burro, Catalina, Miguel, the Colombians...). If someone wants to do a fully Neutral Spanish translation, it should use a new file instead of overwriting this one in a translation war.