v0.23.0-rc1

• Support for Fischer Random Chess (UCI_Chess960 option to enable FRC-style castling). Also added support for FRC-compatible weight files, but no training code yet.
• New option --logit-q (UCI: LogitQ). Changes subtree selection algorithm a bit, possibly making it stronger (experimental, default off).
• Lc0 now reports WDL score. To enable it, use --wdl-info command-line argument or UCI_WdlInfo UCI option.
• Added "Badgame split" mode during the training. After the engine makes inferior move due to temperature, the game is branched and later the game is replayed from the position of the branch.
• Added experimental --short-sightedness (UCI: ShortSightedness) parameter. Treats longer variations as more "drawish".
• Lc0 can now open Fat Fritz weight files.
• Time management code refactoring. No functional changes, but will make time management changes easier.
• Lc0 logo is now printed in red! \o/
• Command line argument -v is now short for --verbose-move-stats.
• Errors in --backend-opts parameter syntax are now reported.
• The most basic version of "certainty propagation" feature (actually without "propagation"). If the engine sees checkmate, it plays it! (before it could play other good move).
• Various small changes: hidden options to control Dirichlet noise, floating point optimizations, Better error reporting if there is exception in worker thread, better error messages in CUDA backend.