Adding pt doc "Testing Components and Controllers"

I tried to write this doc about "Testing Components and Controllers".
The text I based on discussions on the mailing list and docs from VRaptor3.

Just in portuguese, so when you accept the doc, I can try translate to English.  :smiley: 

Sorry for some possible errors.
I think change this to: "Primeiramente vamos abordar apenas o cado de validação do próprio Validator do VRaptor."