[tldoc] Updated PT-BR translation

[Karl Berry]

Hi Paulo,

    https://github.com/cereda/texlive-ptbr

Updated, thanks.

    Out of curiosity, I left the original comment lines (#~) in the .po file 
    (I used the pt_br.po version from TL2012). Maybe we could remove those 
    lines?

I'm not sure what you mean, since the string "#~" does not appear in
your file.  Anyway, feel free to remove whatever makes sense (or not :) ..

k