MEDIUM: http: add the "set-mark" action on http-request/http-response rules

"set-mark" is used to set the Netfilter MARK on all packets sent to the
client to the value passed in <mark> on platforms which support it. This
value is an unsigned 32 bit value which can be matched by netfilter and
by the routing table. It can be expressed both in decimal or hexadecimal
format (prefixed by "0x"). This can be useful to force certain packets to
take a different route (for example a cheaper network path for bulk
downloads). This works on Linux kernels 2.6.32 and above and requires
admin privileges.
diff --git a/include/types/proto_http.h b/include/types/proto_http.h
index 89980b1..1d7c92f 100644
--- a/include/types/proto_http.h
+++ b/include/types/proto_http.h
@@ -249,6 +249,7 @@
 	HTTP_REQ_ACT_SET_NICE,
 	HTTP_REQ_ACT_SET_LOGL,
 	HTTP_REQ_ACT_SET_TOS,
+	HTTP_REQ_ACT_SET_MARK,
 	HTTP_REQ_ACT_MAX /* must always be last */
 };
 
@@ -262,6 +263,7 @@
 	HTTP_RES_ACT_SET_NICE,
 	HTTP_RES_ACT_SET_LOGL,
 	HTTP_RES_ACT_SET_TOS,
+	HTTP_RES_ACT_SET_MARK,
 	HTTP_RES_ACT_MAX /* must always be last */
 };
 
@@ -377,6 +379,7 @@
 		int nice;                      /* nice value for HTTP_REQ_ACT_SET_NICE */
 		int loglevel;                  /* log-level value for HTTP_REQ_ACT_SET_LOGL */
 		int tos;                       /* tos value for HTTP_REQ_ACT_SET_TOS */
+		int mark;                      /* nfmark value for HTTP_REQ_ACT_SET_MARK */
 	} arg;                                 /* arguments used by some actions */
 };
 
@@ -393,6 +396,7 @@
 		int nice;                      /* nice value for HTTP_RES_ACT_SET_NICE */
 		int loglevel;                  /* log-level value for HTTP_RES_ACT_SET_LOGL */
 		int tos;                       /* tos value for HTTP_RES_ACT_SET_TOS */
+		int mark;                      /* nfmark value for HTTP_RES_ACT_SET_MARK */
 	} arg;                                 /* arguments used by some actions */
 };