Update copyright dates to 2019. (KhronosGroup#41)

Update source to v2.2-9

This directly updates from the v2.2-3 source to v2.2-9 source.  The
specification was ported from Asciidoc to Asciidoctor in this period, and thus
this update touches every part of the specification.

Initial commit for OpenCL 2.2 spec release.