New automated test doing the roundrtrip of group-type related APINote that this is currently failing due to a bug in package_instantiate_object, which triggered the creation of this test.
Make 'util_user_message' quote the message when the parameter 'html_p' is false, not otherwise, restoring pre-refactoring behavior and making it coherent with the parameter doc
Bugfixes et al: - don't throw a server error if one clicks submit on the empty form without specifying a file - allow to upload the same zipfile multiple times without throwing an error - streamline idioms