Update Brazilian Portuguese translation

[katananja]

To future Brazilian Portuguese translators, this translation is done following basic Brazilian Portuguese grammar, we try to keep the "norma culta" and/or "norma-padrão". When possible:

• Avoid word contractions or abbreviations like "pra" instead of "para", etc.
• There are around 13 rules on how to use capital letters in Brazilian Portuguese, avoid "Escrever Deste Jeito", "Escreva deste jeito".
• Make use of Brazilian Portuguese articles (o, a, os, as, um, uns, uma, umas).
• Avoid literal translations like coin = "moeda", we never used "moeda" to play, we use "ficha", etc.
• For lack of a better nomenclature, some times we have to translate the meaning of what the action or word does and not the literal translation of it (aka versão brasileira). For instance, the "parent" terminology MAME uses, in this case, "parent" means an organized structure the ROM belong to, in pt_BR this was literally translated as "pai/pais" (father/mother parenthood related), in this case, "principal" (main/root) was chosen so anyone without a technical background can understand what it means. This is one example, you might find another along the translation.
• When possible, try to avoid "estrangeirismos", if our language have a word for something, use it. Use "excluir" instead of "deletar" (to delete), use "redefinir" instead of "resetar" (to reset), use "encerrar" instead of "sair" (to quit), etc.
• Do not delete the name/alias of the people that came before you, some people dedicated hours, days, months working on this translation.
• This is not a competition, there's no prizes to win, we are just trying to give our best to those that doesn't understand English. If you find something wrong, send a pull request, but try to keep up with the grammar standards.