Use pt-BR for Portuguese (Brazil) and pt for Portuguese (Portugal)

Portuguese (Brazil) is only used in Brazil, whereas Portuguese
(Portugal) is used in other Portuguese-speaking countries. Therefore,
it is standard practice to have a pt and pt-BR translation. I don't
know why the eyes-free port of eSpeak decided to do things
differently.
Updated the Brazillian Portuguese translations (translator: Cleverson Casarin Uliana)
Map the pt-BR strings.xml location for Transifex (the Android resource locale code is non-standard).
Use the Transifex formatting for the pt-BR translation.
Fix translation issues that were breaking the build.