update a2.3

main changes:

• replays; best replays are automatically saved and used as ghosts, replays can also be saved manually for the most recent run and selected as the ghost
• changed main menu UI to be cleaner
• added saving the last run's debug info, useful for diagnosing bugs that havent been recorded manually or arent easily replicable
• changed Cave starting position to match CaveShort

bug fixes:

• fixed the ability to cheese the timer by loading in the world while left click is held
• fixed a bug where pressing join with no server connection, and then going back to singleplayer, prevents finishing