elnode-cached: send bodyless 304 response
elnode-http-return: take the unnecessary progn out
elnode-send-file: use a function to decide whether to send with a process or not
elnode-modified-since: reduce the precision in order to compare times better
elnode--webserver-handler-proc: reformat the if
elnode--child-process-sentinel: simplify with better lisp
elnode-rfc1123-date: new alias to allow elnode--rfc1123-date to be called by user code
elnode-proxy-do: add a header-filter to allow origin response headers to be hacked