MEDIUM: http: add support for "http-request redirect" rules

These are exactly the same as the classic redirect rules except
that they can be interleaved with other http-request rules for
more flexibility.

The redirect parser should probably be changed to stop at the condition
so that the caller puts its own condition pointer. At the moment, the
redirect rule and condition are parsed at once by build_redirect_rule()
and the condition is assigned to the http_req_rule.
diff --git a/include/types/proto_http.h b/include/types/proto_http.h
index 7c5a42a..ef81a12 100644
--- a/include/types/proto_http.h
+++ b/include/types/proto_http.h
@@ -243,6 +243,7 @@
 	HTTP_REQ_ACT_AUTH,
 	HTTP_REQ_ACT_ADD_HDR,
 	HTTP_REQ_ACT_SET_HDR,
+	HTTP_REQ_ACT_REDIR,
 	HTTP_REQ_ACT_MAX /* must always be last */
 };
 
@@ -354,6 +355,7 @@
 			int name_len;          /* header name's length */
 			struct list fmt;       /* log-format compatible expression */
 		} hdr_add;                     /* args used by "add-header" and "set-header" */
+		struct redirect_rule *redir;   /* redirect rule or "http-request redirect" */
 	} arg;                                 /* arguments used by some actions */
 };