add: macro endpoints

add: basic macro support
fix: database locking with lock-pointer
fix: memory leaks

src/endpoints/api_v1_schedules_STR.c

@@ -226,7 +226,8 @@ api_v1_schedules_STR_DELETE(struct mg_connection *nc, struct http_message *hm, e
     }
     else
     {
-        endpoint_response_text(response, 200, "", 0);
+        static const char content[] = "deleted schedule";
+        endpoint_response_text(response, 200, content, STRLEN(content));
     }
     schedule_free(schedule);
     return;