MINOR: http: Add 404 to http-request deny

This patch adds http status code 404 Not Found to http-request deny. See
issue #80.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 69daaa8..d0bb974 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -373,6 +373,7 @@
    401  when an authentication is required to perform the action (when
         accessing the stats page)
    403  when a request is forbidden by a "http-request deny" rule
+   404  when the requested resource could not be found
    408  when the request timeout strikes before the request is complete
    410  when the requested resource is no longer available and will not
         be available again
@@ -3607,8 +3608,8 @@
                                  yes   |    yes   |   yes  |   yes
   Arguments :
     <code>    is the HTTP status code. Currently, HAProxy is capable of
-              generating codes 200, 400, 403, 405, 408, 410, 425, 429, 500, 502,
-              503, and 504.
+              generating codes 200, 400, 403, 404, 405, 408, 410, 425, 429, 500,
+              502, 503, and 504.
 
     <file>    designates a file containing the full HTTP response. It is
               recommended to follow the common practice of appending ".http" to
@@ -3656,8 +3657,8 @@
                                  yes   |    yes   |   yes  |   yes
   Arguments :
     <code>    is the HTTP status code. Currently, HAProxy is capable of
-              generating codes 200, 400, 403, 405, 408, 410, 425, 429, 500, 502,
-              503, and 504.
+              generating codes 200, 400, 403, 404, 405, 408, 410, 425, 429, 500,
+              502, 503, and 504.
 
     <url>     it is the exact contents of the "Location" header. It may contain
               either a relative URI to an error page hosted on the same site,
@@ -3688,8 +3689,8 @@
                                  yes   |    yes   |   yes  |   yes
   Arguments :
     <code>    is the HTTP status code. Currently, HAProxy is capable of
-              generating codes 200, 400, 403, 405, 408, 410, 425, 429, 500, 502,
-              503, and 504.
+              generating codes 200, 400, 403, 404, 405, 408, 410, 425, 429, 500,
+              502, 503, and 504.
 
     <url>     it is the exact contents of the "Location" header. It may contain
               either a relative URI to an error page hosted on the same site,