WIP: Export of group content
requested to merge 196-feature-request-ability-to-export-and-move-a-group-to-a-second-crabgrass-instance into master
everybody who is allowed to destroy a group can create an archive for download archive now contains wiki pages and attachments and assets from asset pages and a short README file archives are created asynchronously
additional changes:
- zip-zip is not used anymore, removed dependency and commented out code (gallery does not accept zip file uploads)
- print preview of wiki pages now contains posts
Closes #196
Edited by dgt