[imp] About the translation effort (pt_BR)

[Fábio Almeida]

There are lots of new strings to be translated for the pt_br version of IMP,
but I'm currently trying out 4.2 RC-2. Should I wait for the official
4.2stable (or rephrasing, will I be wasting my time if I translate
this RC?).
Also, how can I tell if someone else is still working on the translation or
just abandoned it? The "new message" string for instance, seems not to be
translated for years now.