Fix: Do not pass $next handler to final request handler.
(#308 by @clue)

Fix: Fix awaiting queued handlers when cancelling a queued handler.
(#313 by @clue)

Fix: Fix Server to skip SERVER_ADDR params for Unix domain sockets (UDS).
(#307 by @clue)

Documentation for PSR-15 middleware and minor documentation improvements.
(#314 by @clue and #297, #298 and #310 by @seregazhuk)

Minor code improvements and micro optimizations.
(#301 by @seregazhuk and #305 by @kalessil)