zip 3.0.1

• The progress bar option is now named zip_progress, to match the other
  options. The old zip.progress name still works as a fallback (#150).

• Boolean environment variables (R_ZIP_PROCESS_FALLBACK and
  ZIP_PROGRESS currently) are now matched case-insensitively, so TRUE
  and FALSE are accepted as documented (#154).

• The number of threads used by unzip() now respects the Ncpus option,
  if neither the zip_threads option nor the ZIP_THREADS environment
  variable is set (#151).

• Archives created by zip() can now always be extracted with the Windows
  Explorer "Extract All" tool, including archives that contain many small
  files (#153).