Added support for the use vectors of time steps in most short-term metrics. It is more computationally efficient and ergonomic to do this rather than calculating short-term metrics for each individual time step. Some key points:
When vector inputs are used for time steps, the result is contained in a list
The names of the entries in the list are character versions of the corresponding time step values
Time step vectors must consist of ordered positive integers with no duplicate values
Time step vector inputs have not been added for short-term metrics that return dense matrices
Updated the map() function to support list inputs generated by the short-term metrics. The result is a list of RasterLayers
Updated the Temporal Analysis and Animations vignettes to incorporate time step vectors
Created a Gitter community for package support. Gitter badges on the README and home pages can be used to access it.