When we generate links from URL's in messages, we add rel="nofollow" to combat link spam. This change turns that into rel="nofollow noopener". This prevents the page at the end of the link from having access to the roundup window that displays the link. Details on the issue are are at: https://mathiasbynens.github.io/rel-noopener/ search web for noopener vulnerability. This problem usually requires a target="_blank" to really exploit it and we don't provide that. But adding noopener is extra protection.

recursive-include share *
recursive-include roundup *.*
recursive-include frontends *.*
recursive-include scripts *.* *-*
recursive-include tools *.* base64
recursive-include test *.py *.txt
recursive-include doc *.html *.png *.txt *.css *.example
recursive-include detectors *.py README.txt
global-exclude *.pyc *.pyo .DS_Store *.orig *.rej *~ \#*
include run_tests.py demo.py *.txt
include doc/conf.py doc/roundup-favicon.ico
exclude doc/security.txt
include locale/*.po locale/*.mo locale/roundup.pot