Better HTTPD logging, and fix a file-responder bug

contrib/httpd/file-responder.factor

@@ -32,12 +32,12 @@ parser sequences strings ;
      "method" get "head" = [
         drop
     ] [
-        "request" get [ directory. ] simple-html-document
+        "request" get [ dup log-message directory. ] simple-html-document
     ] if ;
 
 : serve-directory ( filename -- )
-    "/" ?tail [
-        dup "/index.html" append dup exists? [
+    "/" over tail? [
+        dup "index.html" append dup exists? [
             nip serve-file
         ] [
             drop list-directory

contrib/httpd/responder.factor

@@ -62,10 +62,10 @@ SYMBOL: responders
     "Content-Length" swap hash dup
     [ string>number read query>hash ] when ;
 
-: log-user-agent ( hash -- )
-    "User-Agent" swap hash [
-        [ "User Agent: " % ": " % % ] "" make log-message
-    ] when* ;
+: log-headers ( hash -- )
+    [
+        drop { "User-Agent" "X-Forwarded-For" "Host" } member?
+    ] hash-subset [ ": " swap append3 log-message ] hash-each ;
 
 : prepare-url ( url -- url )
     #! This is executed in the with-request namespace.
@@ -75,7 +75,7 @@ SYMBOL: responders
 
 : prepare-header ( -- )
     read-header dup "header" set
-    dup log-user-agent
+    dup log-headers
     read-post-request "response" set ;
 
 ! Responders are called in a new namespace with these