OSL v1.11.17.0 release

Larry Gritz

We have tagged v1.11.17.0 and updated the "release" branch marker to this point, as the latest supported production release of OSL. This is guaranteed to be API, ABI, and link backward-compatible with prior 1.11.* releases.

Release -- 7 Jan 2022 (compared to
* Fix in runtime optimizer where tracking of messages and unknown messages
relied on uninitialized variables. #1447
* Minor changes related to OpenColorIO changing their master branch name to
"main". #1431
* Testing: Get texture3d tests operational again. #1437
* Docs: Fix missing "errormessage" explanation for environment() and
texture3d(). #1442
* Build/cmake fixes: Make PROJECT_VERSION_RELEASE_TYPE and
OSL_SUPPORTED_RELEASE be cache strings, so they can be overridden; change
OSL_IS_SUBPROJECT to PROJECT_IS_TOP_LEVEL (and change its sense) to match
CMake 21+ behavior; add a TIME_COMMANDS option to help debug performance of
the build. #1443

Larry Gritz