MEDIUM: add set-priority-class and set-priority-offset

This adds the set-priority-class and set-priority-offset actions to
http-request and tcp-request content. At this point they are not used
yet, which is the purpose of the next commit, but all the logic to
set and clear the values is there.
diff --git a/include/proto/queue.h b/include/proto/queue.h
index 166da12..28709fa 100644
--- a/include/proto/queue.h
+++ b/include/proto/queue.h
@@ -90,6 +90,25 @@
 		(!s->maxconn || s->cur_sess < srv_dynamic_maxconn(s)));
 }
 
+static inline int queue_limit_class(int class)
+{
+	if (class < -0x7ff)
+		return -0x7ff;
+	if (class > 0x7ff)
+		return 0x7ff;
+	return class;
+}
+
+static inline int queue_limit_offset(int offset)
+{
+	if (offset < -0x7ffff)
+		return -0x7ffff;
+	if (offset > 0x7ffff)
+		return 0x7ffff;
+	return offset;
+}
+
+
 #endif /* _PROTO_QUEUE_H */
 
 /*