Maintain a circular buffer of recent commands, add to crashlog.

Add console command to dump command log.
Increase max crashlog size.

src/openttd.cpp

@@ -331,6 +331,8 @@ static void ShutdownGame()
 	FioCloseAll();
 
 	UninitFreeType();
+
+	ClearCommandLog();
 }
 
 /**