No cancel signal to the Publisher of a streaming client request

[rstoyanchev]

Symmetrical to #283, this ticket is for client to server streaming. If the client is not writing for some period of time, it remains unaware of a server shutdown. On the next attempt to write, the client response gets an error notification.

[razorcd]

can you give us an update on the issue?
We are looking forward to this fix.

[trovanfloyd]

I'm also interested on this solution to be done :)

[violetagg]

@rstoyanchev I think that this PR #1480 will address this issue. We instruct Netty to read once we send the headers.