Security updates for Wednesday

Security updates have been issued by Debian (heimdal, libarchive, and nginx), Fedora (varnish-modules and xterm), Red Hat (firefox), Scientific Linux (firefox, hsqldb, and thunderbird), SUSE (Botan, colord, containerized-data-importer, ffmpeg-4, java-1_8_0-ibm, krb5, nginx, redis, strongswan, tomcat, and xtrabackup), and Ubuntu (apr-util, freerdp2, and sysstat).