v0.2.3

The game now updates itself: install this version by hand once, and later releases are offered on the title and put in place for you.

Added

• Updates: the game checks GitHub for a newer release at startup and offers it on the title, with its notes.
• Updates: Update now downloads it with a progress bar, checks it against its checksum, installs it and restarts the game.
• Updates: Later, Skip this version, and Updates (Ask / Automatic / Off) and Check for updates in Settings.
• Updates: the mods folder, logs, saves and settings are kept; a failed update puts every file back.