CVE-2017-10971 and CVE-2017-10972: apply fixes to the event loop from

https://cgit.freedesktop.org/xorg/xserver/commit/?id=ba336b24052122b136486961c82deac76bbde455
https://cgit.freedesktop.org/xorg/xserver/commit/?id=8caed4df36b1f802b4992edcfd282cbeeec35d9d
https://cgit.freedesktop.org/xorg/xserver/commit/?id=215f894965df5fb0bb45b107d84524e700d2073c
https://cgit.freedesktop.org/xorg/xserver/commit/?id=05442de962d3dc624f79fc1a00eca3ffc5489ced

XXX: pullup-[678] (6/7 also need xfree port.)

initial import of existing netbsd xorg-server 1.10 sources in the
xorg-server.old subdir.