Security updates for Wednesday

Security updates have been issued by Arch Linux (webkit2gtk), Debian (kernel and libav), Fedora (c3p0 and community-mysql), Scientific Linux (pacemaker), SUSE (axis, libtasn1, NetworkManager, sles12sp3-docker-image, sles12sp4-image, system-user-root, and xen), and Ubuntu (freerdp, GNU Screen, keepalived, and thunderbird).