Added simple kernel and setup so that CMake copies this kernel
into build directory.
Improved CMake method for copying kernels. We nolonger use
configure_file so a change in a kernel does not trigger everything
to be rebuilt.

Instead everytime we build the kernels are copied across.
run_kernel now runs a kernel :) . A lot of work needs doing to
improve libclprobe to cut down OpenCL's boiler plate code.