New build system for es.utf, pt.utf8, pt_BR.utf8



Hi!

I've committed new build system for pt.utf8, es.utf8 and pt_BR.utf8. 
The most important change is that it is no longer needed to
maintain two copies of maxima.texi in /<lang> and /<lang>.utf8.
Make imports all required data from /<lang> and recodes it to utf8. 
maximahtml.mk files no longer in use either.

With best regards,

Vadim

-- 
      Vadim V. Zhytnikov

       <vvzhy at mail.ru>
      <vvzhy at netorn.ru>