The classes Decoder and Interpolator now inherit common methods from a new class, Track. The new class is fully compatible with the overall workflow and enables users to create an instance from formatted data only. This instance can be used to join or patch data from multiple GPX/FIT files using a new tool, which was also added.
A problem with satellite maps from Mapbox.com was identified and is going to be investigated further. (some tiles in some zoom values do not render at all, presumably the problem is on the Mapbox.com side)