Install OpenCL

Dear Quirin,

To be able to install OpenCL on 
ArchLinux, I needed to install 
opencl-headers first, because my system 
complained about CL/opencl.h ...  Maybe 
there is something like that on Windows 
... 

Best,
Rasmus

[1] https://archlinux.org/packages/extra/any/opencl-headers/