Allow runtime changes to service parameters

General service parameters can now be altered at runtime.

server/core/maxscale/config_runtime.h

@@ -120,6 +120,17 @@ bool runtime_enable_server_ssl(SERVER *server, const char *key, const char *cert
  */
 bool runtime_alter_monitor(MXS_MONITOR *monitor, const char *key, const char *value);
 
+/**
+ * @brief Alter service parameters
+ *
+ * @param monitor Service to alter
+ * @param key     Key to modify
+ * @param value   New value
+ *
+ * @return True if @c key was one of the supported parameters
+ */
+bool runtime_alter_service(SERVICE *service, const char* zKey, const char* zValue);
+
 /**
  * @brief Create a new listener for a service
  *