Changes in version 1.4 (2026-06-09)

* Added DOI reference for van Renswoude et al. (2018) to DESCRIPTION and
  all man pages.
* Replaced print() calls used for informational/warning messages with
  warning() (GazePath.R) and message() (summary.gazepath.R), in line with
  CRAN policy on console output.
* Excluded non-package files (.eml, AGENTS.md) from the built tarball via
  .Rbuildignore.
* Fixed a typo in the summary.gazepath warning message
  ("particpant" -> "participant").