keep a copy of khronos headers

[chivakker]

Can this program/library do something with the headers? Keep a copy of the version supported or add them as a git submodule? This will result on a building experience less complex.

[iwwu]

A copy of opencl_headers is required by our BiFModule compilation. We'll evaluate the request and keep you updated.

[iwwu]

I will need to make 1 more change to switch the code using the default copy of opencl_headers. Once the change is made, I will update README.

[iwwu]

The user is no longer required to download opencl_headers separately. README is updated.
Available in igc_release_2019-01-15