The future of cpuminer-opt.

A number of things are converging that require some decisions to be made.

After 7 years I think I've squeezed about as much juice from cpuminer as I can. I have a couple more small optimisations so there will be,
at least, one more release.

cpuminer-opt's usefulness is diminishing fast, and falling further behind GPUs. CPUs can't provide large generational performance increases
that GPUs do. The crypto bear market isn't helping.

I'm not sure what I'll do or when but it seems the end is in sight.