I've just published a php tool that may be useful for managing .pot/.po/.mo files for packages.

Just download the two files base.php and i18n.php from
https://github.com/concrete5/concrete5/pull/670/files...

and launch the following command:
php i18n.php --webroot=RootFolderOfConcrete5 --interactive
(or php i18n.php --help for more options)

With this utility you'll be able to create the .pot file (the template used as "base" for all the translations), the .po files for the languages, and the .mo files from the .po file.

(Please remark that the .po files are the one that should be translated with poedit or betterpoeditor)