[PATCH] Introduce CLC_VERSION macros v2

Add these out-of-order in clc.h so we can use these in other headers.

v2: Take into account the lack of a definition in OpenCL 1.0

Add these out-of-order in clc.h so we can use these in other headers.

v2: Take into account the lack of a definition in OpenCL 1.0

LGTM.

Committed. Thanks for the review.

Jeroen