Packages which uses com_err frequently have no built-in facility for using
localized messages.

The etpo program walks a directory tree containing .et files used by
compile_et, and produces a .pot file suitable for use with GNU gettext on
stdout.  Translations can then be made for the package which uses com_err,
and consumers of those messages can then use gettext to obtain localized
forms of messages returned by the error_message() function.
