Add streaming capabilities

[nicolas-graves]

Thanks for the library !

Let's say we're reading from a port/stream that has multiple concatenated bencode messages. Is there a way to handle that efficiently in this bencode library (I don't see it in documentation) ? What I mean by efficiently is not having to brute force every possible combination in a concatenation of bencode messages, but reading gradually, and stopping / composing a list of bencode message while the port/stream is read.