So, after much pfaffing - my C++/OpenCL pipeline implementation is just starting to come alive! :D

Previously it was using Apple GCD, however it quickly became clear that GCD's ability to sort out it's concurrency (it has it's own cl_command_queue) isn't strong part.. but I'm happy that it's starting to execute kernels and it shouldn't be too long before the pipeline is back at full tilt with some much needed OO refactoring :)

This makes it rather portable too :D