Prosposal: enhanced logging and debugging

[dmcgowan]

Libchan can be difficult to debug network interactions through traditional packet sniffing. Because of the lack of tooling which currently exists around debugging spdy, libchan should have a debug mechanism which is spdy stream and channel aware. Debug level logging as well as efficient info level logging will be needed by applications using libchan.

Example usage would be for docker-archive/docker-registry#635

[mcollina]

I think it is really an hard topic. Packet sniffing is out of question due to a) multiple transports b) multiplexing c) encryption (for SPDY and HTTP2). So, we should have some kind of prescribed logging format and a tool to visualize the thing: monitoring live channels can be a thing that smooth adoption.

[dmcgowan]

Adding to 0.2.1 for an implementation of the stream provider interface which does packet capturing and forwarding to another stream provider.