* ocl-icd: fix build problems
* New package: opencl-c-headers
* New package: opencl-clhpp
* New bundled package: opencl-headers
- bundle C and C++ header files
* ocl-icd: Add +headers variant to use this as opencl provider
* ocl-icd: add new upstream release 2.2.13
* ocl-icd: add asciidoc-py3 and xmlto dependency needed for manpage generation
* ocl-icd and opencl-headers provides OpenCL 3.0
- also add more explicit version providing for older ocl-icd versions
* opencl-headers: add maximum of supported opencl versions for all versions
* opencl-headers: there aren't final releases with OpenCL 3.0
6a82b2260f