Merge branch 'master' into feature/expand-http-payload-support

db/patch-monitor-add-resend-interval.sql

@@ -0,0 +1,10 @@
+-- You should not modify if this have pushed to Github, unless it does serious wrong with the db.
+BEGIN TRANSACTION;
+
+ALTER TABLE monitor
+    ADD resend_interval INTEGER default 0 not null;
+
+ALTER TABLE heartbeat
+    ADD down_count INTEGER default 0 not null;
+
+COMMIT;