MFH: r451632

Fix security issues: CVE-2017-13721 and CVE-2017-13723 in xorg-server.
Bump all the slaves due to not being sure where the shared code is used.

Security: 4f8ffb9c-f388-4fbd-b90f-b3131559d888

Approved by: ports-secteam (swills@)