Fix for Chessbox bug FS#10363

Chessbox was overflowing GameList[240] causing the board to flip + crash

GameCnt changed to unsigned char which allows the array to roll over
to 0 after 255

define MAX_GAME_CNT 256 and GameList[MAX_GAME_CNT] along with 1 byte GameCnt
should fix this issue

dbg save routine left in for now to help identify any other problems

Added bounds checking to prevent second bug found when loading .pgn files

Change-Id: I2b615c8ecbed4368724412f80ce07346f3cf30a7
4 files changed