Clear hash on new game in CECP

Ensures reproducible results on repeated searches, e.g.:
```
xboard
new
go
new
go
```

Closes #80.

diff --git a/src/xboard.cpp b/src/xboard.cpp
index fdadf22..69e7252 100644 (file)
--- a/src/xboard.cpp
+++ b/src/xboard.cpp
@@ -122,6 +122,7 @@ void StateMachine::process_command(Position& pos, std::string token, std::istrin
   }
   else if (token == "new")
   {
+      Search::clear();
       setboard(pos, states);
       // play second by default
       playColor = ~pos.side_to_move();