lib-http: server: Perform output stream error handling in one place.

lib-http: server: Handle output stream errors in a separate function.

lib-http: server: Allow determining at any time whether the connection will be closed after handling a request. Previously, this was only possible during response submission, which potentially requires making a `close' parameter available for any API function that submits a (failure) response. This would become very ugly and inflexible.

lib-http: server: Implemented API for handling the incoming request payload in the background. It allows forwarding the incoming payload to an output stream (e.g. iostream-temp) or to a buffer. The maximum size of the payload is configurable. The client will get a 413 error if the maximum is exceeded.

lib-http: server: Explicitly record the number of references held for a request by the application from within the callback.

lib-http: server: Changed http_server_request_is_complete() from an inline to a normal function.

lib-http: server: Restructured http-server-private.h.

global: unsigned int:1 -> bool:1 perl -i -pe 's/unsigned int ([^,:;]+):1;/bool $1:1;/' **/*.[ch]

lib-http: server: Implemented means to gracefully shut down the server. While shutting down, it will not accept new requests and connections are closed once they become idle.

lib-http: server: Implemented blocking request input stream.

lib-http: server: Implemented blocking response output stream.

lib-http: server: Created blocking http_server_response_send_payload() API that closely mimics the client equivalent. It allows sending response payload in several chunks in a blocking fashion.

lib-http: server: Added some request debug logging.

lib-http: server: Fixed connection reference counting. Connection often still got destroyed too early. Particularly submitting responses would potentially destroy the connection, which is often unexpected. Sending responses is now postponed until handled by the stream output handler, which is explicitly triggered when necessary.

lib-http: server: Added support for authentication.

lib-http: server_request/connection - improve encapsulation It just feels a bit dirty having the request mess around with the connection's internals, have the connection manage its linked lists itself. No functional changes. Signed-off-by: Phil Carmody <phil@dovecot.fi>

lib-http server: Delay calling the request's destroy callback until handle_request() callback is finished. This simplifies the code in the handle_request() so it doesn't need to keep track of whether the response is already submitted or not.

lib-http server: Call request destroy callback immediately after response is finished sending. Regardless of any other references to the request.

lib-http: server: Fixed server waiting for payload of already failed request.

lib-http server: Made http_server_request_[un]ref() public. Also http_server_request_unref() now returns if this was the last reference or not.

lib-http: Added initial support for server-side HTTP API.