add spec for chunked response with "Connection: close" header.
add spec for chunked response with pipelined request.
handle connection state properly when the response is chunked.
combined chunked response specs.
reset request state when response state is set to the initial state.
Merge pull request #112 from unakatsuo/fix-chunked-with-connclose

Socket closed unexpectedly for chunked response with "Connection: close" request