MINOR: http: prepare support for parsing redirect actions on responses

In order to support http-response redirect, the parsing needs to be
adapted a little bit to only support the "location" type, and to
adjust the log-format parser so that it knows the direction of the
sample fetch calls.
diff --git a/include/proto/proto_http.h b/include/proto/proto_http.h
index 41a7dc6..5f1ac1f 100644
--- a/include/proto/proto_http.h
+++ b/include/proto/proto_http.h
@@ -125,7 +125,7 @@
 void free_http_res_rules(struct list *r);
 struct chunk *http_error_message(struct stream *s, int msgnum);
 struct redirect_rule *http_parse_redirect_rule(const char *file, int linenum, struct proxy *curproxy,
-                                               const char **args, char **errmsg, int use_fmt);
+                                               const char **args, char **errmsg, int use_fmt, int dir);
 int smp_fetch_cookie(const struct arg *args, struct sample *smp, const char *kw, void *private);
 int smp_fetch_base32(const struct arg *args, struct sample *smp, const char *kw, void *private);