@dhgutteridge: Unsigned add-ons work exactly the same as FF43, they're disabled by default but work if you toggle xpinstall.signatures.required to false in about:config. The unconditional disabling was delayed to FF46, scheduled for April. See https://blog.mozilla.org/addons/2016/01/22/add-on-signing-update/ .
This has downgraded the previous stable version bzip2-1.0.6-19.fc23. This is due to bodhi allowing downgraded packages in stable releases - see https://bugzilla.redhat.com/show_bug.cgi?id=1292914 . Dgilmore should be able to restore -19 by request, which in my opinion would be the clean way to deal with this, or you can just submit a bump update, which is what the libpng packager just did when it happened to that package.
If this is only being submitted to work around the fact that mistakenly downgraded this package, I think it would be better all around to just ask dgilmore to fix that and put 1.6.19-1 back where it belongs. He was able to do it when qemu was downgraded. See https://bugzilla.redhat.com/show_bug.cgi?id=1292914 .
Resolving Dependencies --> Running transaction check ---> Package kf5-kdesu.x86_64 0:5.14.0-1.fc23 will be updated ---> Package kf5-kdesu.x86_64 0:5.15.0-2.fc23 will be an update --> Processing Dependency: kf5-filesystem >= 5.15.0 for package: kf5-kdesu-5.15.0-2.fc23.x86_64
Packages skipped because of dependency problems: kf5-kdesu-5.15.0-2.fc23.x86_64 from updates
Have not tested, but is expected to have a popup bug which is fixed by https://bodhi.fedoraproject.org/updates/FEDORA-2015-908d9aa6c4 (gnome-shell-extension-openweather-1-0.7.20151017git34aa242.fc23).