Issue #237: indicate ownership of repo groups and user groups (conservancy/kallithea)

[Dominik Ruf]

New issue 237: indicate ownership of repo groups and user groups
https://bitbucket.org/conservancy/kallithea/issues/237/indicate-ownership-of-repo-groups-and-user

Dominik Ruf:

Let's say you want to delete an old user but you can't because he is owner of a repo group.
Currently there is not overview repo groups or user groups are owned by this user. And the error message doesn't say either.