Add Portuguese translations (pt and pt-BR)

Patch based on feedback received so far on
https://pt.wikipedia.org/wiki/WP:Esplanada/propostas/Instalação_da_extensão_Education_na_wiki_Pt_(7ago2013)

Change-Id: I5b40747c29f820712ccaa69d303be06cc09a24a0
Merge "Add Portuguese translations (pt and pt-BR)"