#1: Replace busy-waiting with sleep-waiting

[Dumuzy]

Noop-busy-waiting is very bad for several reasons:

• I want to use MadChess' lower elos on Smartphone. It is an absolute no-go to waste battery there with busy-waiting.

• I want to calibrate MadChess' lower elos with longer games. (around 12+3) Noop-busy-waiting is very bad for that, as I can then only run a small amount of games in parallel. With sleep-waiting, I can run 40 or more games in parallel.

ohhh, I probably don't yet understand pull requests correctly. I just wanted you to pull 96c7f06 because of busy waiting and c0f8a0e because MadChess' lower elos only will queen otherwise very late. See this issue: https://github.com/Dumuzy/MadChess/issues/10