Security updates for Wednesday

Security updates have been issued by Debian (libjpeg-turbo and systemd), Fedora (matrix-synapse, mingw-libjpeg-turbo, and mingw-libvorbis), Mageia (libcaca, libmp4v2, libxml2, pdns-recursor, perl-Email-Address, php-pear-HTML_QuickForm, podofo, and wavpack), openSUSE (webkit2gtk3), Red Hat (qemu-kvm-rhev), Scientific Linux (perl), Slackware (httpd), and Ubuntu (ntp).