Drop obsolete "Pointer Events 2 Ext" from SpecData (#1300)
Drop obsolete "Pointer Events 2 Ext" from SpecData (#1300)

The https://w3c.github.io/pointerevents/extension.html spec is now 404;
https://github.com/w3c/pointerevents/commit/add40d9 removed it from the
W3C Pointer Events repo. (The content has been incorporated directly
into the Pointer Events spec.)
jpmedley/kumascript,jpmedley/kumascript