extend variogram to act on lists of telemetry objects, select best dt, and mean the result, like periodogram
document list behavior of periodogram

Move,MoveStack import

overload: subset, [, str

vignette: DOF estimation

variogram: coarsening window method to avoid all bias

proj4: email about making north up

summary.ctmm CIs on boundary estimates with negative curvature

akde with user-specified grid (and projection)

periodogram:  fast, model, averaging, zoom

north vector in telemetry object

contour labels in plot ctmm

Email ks author about inaccuracy

Repeated times in variograms -- account for as error -- fix cap

dplyr, rolling for loops

fix mean parameter for boundary issues

population fit of list
population akde of lists

krige -> predict