v3.01.99-rc4

This is a release-candidate.

As several important pull-requests have been merged, we're starting with rc series, which will be tested in the field for a few days. If no regression or blocking bug is found within ~1 week, the next v3.02.00 stable version will be released.
This rc (rc4) is expected to be the last before the release.

The following changes have been done since the previous rc:

• fix: admins no longer inherited superowner powers