aqhome/mqtt: added messages regarding subscription.

aqhome/mqtt/msg_mqtt.h

@@ -57,5 +57,10 @@ AQHOME_API const char *AQH_MqttMsg_MsgTypeToString(uint8_t t);
 AQHOME_API uint8_t AQH_MqttMsg_GetMsgTypeAndFlags(const GWEN_MSG *msg);
 
 
+/* helper functions */
+AQHOME_API void AQH_MqttMsg_AppendStringWithLen(GWEN_BUFFER *buf, const char *s);
+AQHOME_API int AQH_MqttMsg_DumpString(const uint8_t *ptr, uint32_t len, GWEN_BUFFER *buf);
+
+
 
 #endif