ENH Add an `empty_trajs` classmethod to `Trajectories` to properly handle cases where no data was retrieve from the segmentation
Merge branch 'master' of github.com:bnoi/scikit-tracker
Merge pull request #41 from glyg/master

`empty_trajs` classmethod

Note that `df.empy == True` still works, it's just that what's empty looks more like a Trajectory.