new API for TxReportQueue (fixes #128)

make an idiomatic version of the read size of the java.util.concurrent.BlockingQueue interface.
I don't like CanBuildFrom because I can't catch the types in it, my brain has decided to dislike it :D
I don't like BreakOut because it's something hidden in the API that seems almost magical to people (specially when you read the too long doc for first time) but that is trivial actually...