v1.13

Faster takebacks, and full speed outside the search at fixed speeds.

• Up to 100 plies are now taken back at once instead of 4. Beyond 4 plies the engine used to start a new game and replay every move, at about 0.35 s a ply: after two takebacks in xboard while pondering, a reply took 24 s. Psion takes back 100 plies in about half a second.
• The speed of Cycles, --cycles and UCI_Elo now applies only while Psion searches, from the key that starts the search until it is told to move. Setting up positions, entering moves and taking back run at full speed, so a move costs 40 to 75 ms at any speed (before: about 0.2 s at 2,400 cycles, 1.1 s at 1,000, 5 s at 300). The search runs at the same speed as before, so the UCI_Elo scale is unchanged. The extra time allowed for slow move entry is no longer needed and is gone.

Full Changelog: v1.12...v1.13