USN-4772-1 vnc4 vulnerabilities

USN-2500-1 addressed CVE-2015-0255 for xorg-server. This update provides the corresponding fix for VNC4 on Ubuntu 14.04 ESM and Ubuntu 16.04 ESM. CVE-2015-0255 USN-2726-1 addressed CVE-2015-1283 for Expat. This update provides the corresponding fix for VNC4 on Ubuntu 14.04 ESM and Ubuntu 16.04 ES...