Created base class for proxy models (BaseProxyModel)
Added index() and parent() default implementations to BaseProxyModel
Skeleton of the proxy model for the trajectories
Mapping methods for the trajectories proxy model implemented
Adding the trajectories proxy model to the project
Finished trajectories proxy model (not yet tested)
Removing index() and parent() signatures from DistancesProxyModel
Little adjustment to the index() signature of the base proxy model
Some fixes and adjustments to the linear trajectories proxy
Trajectories proxy model set to the trajectories view