Remove the dependency on httpd_util

Add the function cowboy_clock:rfc1123/1 that formats the given
date to the RFC1123 format.

test/rest_expires.erl

@@ -0,0 +1,22 @@
+-module(rest_expires).
+
+-export([init/3]).
+-export([content_types_provided/2]).
+-export([get_text_plain/2]).
+-export([expires/2]).
+-export([last_modified/2]).
+
+init(_Transport, _Req, _Opts) ->
+	{upgrade, protocol, cowboy_rest}.
+
+content_types_provided(Req, State) ->
+	{[{{<<"text">>, <<"plain">>, []}, get_text_plain}], Req, State}.
+
+get_text_plain(Req, State) ->
+	{<<"This is REST!">>, Req, State}.
+
+expires(Req, State) ->
+	{{{2012, 9, 21}, {22, 36, 14}}, Req, State}.
+
+last_modified(Req, State) ->
+	{{{2012, 9, 21}, {22, 36, 14}}, Req, State}.