Windows 10 RS4 Support for the OpenCL ICD Loader w/ Build Option (#78)

Windows 10 RS4 Support for the OpenCL ICD Loader w/ Build Option (#78)

* Windows 10 RS4 support for OpenCL ICD as per MS directive

Motivation - MS is adopting DCHU complaince and for For RS4 it will be mandatory for OpenCL to load via registry keys contained only within the HKR section of the registry as writes outside of HKR will not be allowed for the INF. It is also to support ParaV feature of the OS to make it "virtualization-ready".

* Update Copyright year
* Fix vendors enumeration on 32-bit Windows OS
* Update CMake file for detecting necessary includes for the Windows WDK
* Add option to build with or without the WDK (default: with)
* Documented Windows WDK dependency