libxml2: update to 2.9.6 (commit: 02ac2fa)
curl: fixCVE-2017-1000099,CVE-2017-1000100,CVE-2017-1000101,CVE-2017-1000254 (commit: 7f2ae86)
libXfont: fix CVE-2017-13720, CVE-2017-13722 (commit: 1be2ea1)
libXfont2: fix CVE-2017-13720, CVE-2017-13722 (commit: 15f735c)