Checker problem with abstract functions

[ffleurey]

The checker complains about several definitions of functions when defining an abstract function which was included from another thing. For example on this file, which I think should be fine (and worked with a previous version): https://github.com/ffleurey/ThingML-PongTutorial/blob/master/src/bounce/ArduinoBounce.thingml

[brice-morin]

Yes, seems like there is an issue there.