Problem:
 * Extract GNOME help translations out of the builds into the translations.tar.gz
 * Park those in Launchpad (Rosetta or Soyuz)
 * Get them back from Launchpad for distributing in language packs

Proposition: upload GNOME help as tarball part of the translation.tar.gz, store in Rosetta, put them verbatim into the translation export
 * Rosetta is not meant to store blobs, infrastructure does not support it
 * Rosetta supports non-PO now (xpi), but it takes very long to set up (full extract of PO files, write tests, etc.)

 -> turned out to not be feasible realistically
 
Long-term solution: Proper support for GNOME help translations in Rosetta
 * Import GNOME help templates and PO files into Rosetta (pkgbinarymangler already exports them)
 * Change pkgbinarymangler to export the translated help images and C help XML file
 * Support translation of images in Rosetta
 * Assemble translated help files in langpack-o-matic, from the exported C help XML file, PO files, and localized images

Alternate proposal which is much easier to implement:
 * during build, create a separate translations-blob.tar.gz in `pkgstriptranslations` and put it into the .changes as type `raw-translations-static`
 * provide support for this in Soyuz to get back the links during langpack build time (See bug Bug:123020)