Split multiple pipelined responses in a list of headers and payloads

[ibnesayeed]

Currently, pipelined responses are treated as a single payload except the first set of headers and iteratively diced and sliced to as needed. This can be improved by preprocessing response and create a list of header and payload pairs. Responses to HEAD request will be little tricky and will need out of band information to split messages properly as they do not have a payload, but headers might suggest that they have one.