Release Rebel 15

[Eduard]

1. New and stronger neural network made from 1.87 billion positions.

2. Estimated strength increase over Rebel 14.2 emulating CCRL 40/2 testing in the range of 80-130 elo.

3. See the Rebel 15 development diary for details.

4. NNUE tuner parameter in Engine Settings. Default setting now 70%.

5. For the moment Rebel 15 is only available as AVX2 engine. It has to be seen if we are still able to provide a weaker SSE version for older computers. NNUE evaluation strongly relies on the AVX2 instruction set and there might come a moment older computers become an obstacle to progress.

....

http://rebel13.nl/windows/rebel-15.html

Is it possible to implement the UCI option "Move Overhead" like in Stockfish? Without an individual setting of Move Overhead, it is not possible to play live online.