I've created a new branch at
https://github.com/Lendog/Mysensors-ESP8266-Wifi-gateway-post-to-thingspeak/tree/My-sensors-library-2.0
I feel a bit slack not properly testing it yet and putting it online, but it compiles fine just haven't loaded it on or tested with sensors. Might need to look into updating a sensor or 2 to run on the new libary