Minor bugfix release

2023-10-11

• Fixed a bug that lead to unity objects and probably whole chunks not correctly being removed when they are no longer needed.
• Added saving the options from the left hand side of the UI, using PlayerPrefs.
• Added basic system that removes entities, which are almost destroyed by the simulation.
• Replaced PreventDarkening by ApplyDarkening for elements for when an explosion occurs. So it's opt in rather than opt out.
• Upgraded the player controller a new version. The player controller should feel way better now.