Clear the layer list widget when clearing the map.
Don’t forget to call parseContinue to parse the whole map file.
Merge branch 'fileio' of https://github.com/dal/RunParticles
When clearing the layer list in the Map, disconnect any signals from the layer first.
QFile is no longer a pointer in the TcxHandler.
Delete the Track instance when destroying the TrackLayer.
Check to make sure we actually got a layer when calling map->getLayer(id).