Release 3.0.1 with security fixes

It's been a while since the last release - I just bumped into the old freemarker issue again, where stacktraces get logged to the html output on production. That is quiet a security mishap. ;-)

#9

We've fixed that long ago, but didn't make it into the 3.0.0 release. Could we do a 3.0.1?

Start by reading issue #9 to understand the already-fixed Freemarker security problem and why it was omitted from 3.0.0. No files or tests are named in this issue, so identify the repository's release entry points before proceeding. Done means a 3.0.1 release is prepared that includes the fix.

Written by the indexing model from the issue text.