v0.7rc1

trackpy v0.7 includes an enhancement/bug fix to how MSD calculations handle gaps
in trajectories. The msd() and imsd() functions now output NaN values (instead
of zeros) for portions of their output that could not be measured. The emsd()
function now properly de-weights missing data, and so its output may be
significantly different (and more accurate) when gaps are numerous and large.

Bug fixes

• MSD properly handles gaps in trajectories (@vivarose, #773)
• Fix plot_traj(colorby='frame') for intermittent particles. (@T0T0R, #777)
• Let imsd() use output of subtract_drift() (@nkeim, #785)

Enhancements

• Clarify what parameters are keyword-only in documentation of link functions
  (@anntzer, #789)