[SM-I18N] Brasilian Portuguese update

[Marcos T. v. L. V. <ma...@v2...>]

Hello,

I put lot of changes in squirrelmail.po.
New translations, correction of some errors & bad translations, etc.
The original squirrelmail.po is from 1.2.7 CVS 
(squirrelmail-20020522_1800-CVS)

Marcos Tadeu