# every release
 - update documentation: README, vignettes, package doc
 - update hyperlinks (to e.g. latest CF version)
 - check deprecated items

# 1.8
 - User-defined calendar
 - equidistant by element and calendar
 - drop stringr dependency - see helpers.R

# Further away
 - cut() needs to support "2 days" etc
 - filter() like tidyverse -> CFsubset
 - CFfactor() can use epochs with lower resolution such as [year, month] for 3-hr data: e.g. daily avg per month per epoch

# Deprecation:
 - Functions in deprecated.R
 - Arguments:
   - Use # DEPRECATED comment inside the function body detailing argument changes
   - In the initial release, support use of the argument but drop documentation
   - 6 months after release, issue a warning
   - 3 months after warning, deprecate
